Non-aqueous silicone emulsions

ABSTRACT

A non-aqueous silicone emulsion containing a silicone phase and an organic phase is useful as a component in various personal care compositions. The silicone phase contains a crosslinked silicone elastomer and a low molecular weight silicone fluid and the organic phase contains an organic liquid.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present invention is a Continuation-In-Part application of U.S.application Ser. No. 09/033,788, filed Mar. 3, 1998, which was aContinuation-In-Part application of U.S. application Ser. No.08/708,436, filed Sep. 5, 1996, U.S. Pat. No. 5,760,116.

FIELD OF THE INVENTION

The present invention relates to non-aqueous emulsions, morespecifically to non-aqueous silicone emulsions.

BACKGROUND OF THE INVENTION

Silicones have many uses in a variety of fields. They have found largecommercial application in products as diverse as sealants, siliconerubbers, adhesives and cosmetics. Silicone oils have been found to beparticularly desirable components of cosmetic compositions because thematerials impart a dry, smooth uniform feel to the cosmetic compositionamong other benefits such as increasing apparent luster (or shine). Thegeneral use of silicones in cosmetic formulations has been complicatedsomewhat by the facts that while lower molecular weight silicones impartdesirable properties to a composition they are volatile and have lowviscosity, while the silicones that overcome these disadvantages areundesirably viscous.

Thus when it has been desirable to utilize low viscosity silicone oilsin a cosmetic application, thickening agents have been employed toincrease the solution viscosity and slow down the evaporative loss ofthe volatile low molecular weight silicone oil. This procedure whileeffective has the disadvantage of decreasing the spreadability of thesilicone oil and leaves a heavy greasy feel on the skin. Thespreadability and dry smooth feel are properties associated with lowviscosity silicone that imparts a desirable feel or hand to thecomposition when it is applied as a cosmetic formulation. Materials thathave found application in attempting to retain the desirable propertiesof low molecular weight silicone oils in cosmetic compositions whilereducing evaporative losses due to high volatility have been amongothers fatty acid esters of dextrin, fatty acid esters of sucrose,trimethylsilyl substituted polyvinyl alcohols, trimethylsilylsubstituted poly saccharides, cellulose ethers containing fatty acidesters, and organically modified clay minerals. These materials have thedisadvantage that the light feeling and spreadability imparted by thelow viscosity silicone oil is changed with the result that thecomposition no longer possesses those properties that suggested the useof the low viscosity silicone oil in the first place. Anotherdisadvantage of these thickening agents or volatility inhibitors is thata large number of them are water soluble and must be used as a waterdispersions or solutions. With hydrophobic silicone oils theintroduction of water thus necessitates the use of emulsifiers andcompatibilizers, complicating the formulation of the cosmetic andgenerally lowering the stability of the formulation with respect toseparation of the component phases.

Recently, another approach to retaining the properties of low viscositysilicone oils in cosmetic compositions has been advanced where the lowviscosity silicone oil is combined with the addition polymerizationproduct between an organohydrogen polysiloxane and an alkenylfunctionalized organopolysiloxane (U.S. Pat. No. 4,987,169). Theorganohydrogen polysiloxane utilized in those formulations comprisedHSiO₁.5 (T^(H)), RSiO₁.5 (T), RHSiO (D^(H)), R₂ SiO (D), R₂ HSiO₀.5(M^(H)) and R₃ SiO₀.5 (M) groups. The crosslinking hydride compoundutilized was thus a compound of the general formula: M_(a) M^(H) _(b)D_(c) D^(H) _(d) T_(e) T^(H) _(f). While the cross-linking compoundadmits T groups either as hydride or substituted by R the preference inthis technology is for linear hydride materials because the additionpolymerization proceeds more smoothly. The R groups in the aboveformulas are typical organic substituents known in the art. Subsequentlya low molecular weight silicone oil is added to the cross-linkedaddition polymerized product and the mixture is treated by applying ashearing force. This material may be used by itself as a cosmeticcomponent or as a thickening agent and has the properties of a greaseand can be used in a wide variety of industrial lubrication applicationsas well as the cosmetic application contemplated. The material preparedin this manner can be regarded as a lightly cross-linked elastomer witha volatile, low molecular weight silicone oil dissolved therein. Becausethe precursor cross-linking hydride is preferably linear and onlymoderately branched when T groups are incorporated, the additionpolymerized product does not possess a tight network of cross-links inthe resulting polymer. Linear and lightly crosslinked networks sufferfrom the disadvantage of having lower efficiency in raising theviscosity of a low molecular weight silicone. In addition to increasingthe cost of the product, higher levels of crosslinked silicones resultin leaving behind more residue when the volatile, low molecular weightsilicone evaporates during use. In some cosmetic applications, e.g.deodorant or antiperspirants, an increased residue is a significantdisadvantage as it contributes to staining of the clothing.

Further, linear and lightly crosslinked silicones do not form a film aseasily as more tightly crosslinked silicones. The lack of a formation ofa film is a disadvantage in a cosmetic application because a filmprovides a softer, smoother feel as compared to the heavier, lessdesirable feel of a linear silicone.

For solids, size reduction processes generally result in changing boththe average particle size and the particle size distribution. With mostsolid materials, size reduction techniques usually reduce the averageparticle size and produce a Gaussian distribution of particle sizes.Consequently, the art dealing with size reduction techniques isprimarily concerned with controlling the width of the Gaussiandistribution, i.e. how broad or how narrow the particle sizedistribution is, a property typically measured by the width of thedistribution peak at half the peak height of the most prevalent particlesize. This is typically referred to as a half-width measurement.

Emulsions can also be subjected to size reduction processes with resultssimilar to those obtained for solid processes. An initial particle sizeand particle size distribution of an immiscible liquid dispersed in asecond liquid phase is converted to one having a smaller averageparticle size. Typically the particle size distribution of thediscontinuous phase in an emulsion is best represented by a Gaussiandistribution regardless of whether the particle size distribution ismeasured before or after size reduction.

While silicones or dispersions of silicones may be emulsified to produceoil-in-water (water is the continuous phase) or water-in-oil (oil is thecontinuous phase) emulsions, emulsions using other extensive orcontinuous solvent phases typically present issues of cost andstability. Non-aqueous emulsions of silicones are useful deliverysystems for cosmetic applications, particularly when the presence ofwater initiates a process that changes the nature of the cosmeticcomposition. While non-aqueous silicone emulsions are known, thoseutilizing lower molecular weight hydroxylic solvents such as alcoholsand glycols typically have sticky or tacky feel and are thus unpleasantwhen applied to the skin. Further, such materials usually require theapplication of a high energy process to prepare the non-aqueousemulsion, e.g. homogenization, which only renders the materialtemporarily stable, i.e. they usually separate after only a few days.

SUMMARY OF THE INVENTION

A non-aqueous silicone emulsion comprises a silicone phase, comprising asilicone elastomer and a low molecular weight silicone compound and anorganic phase, comprising an organic liquid.

The non-aqueous silicone emulsion of the present invention exhibitsunexpectedly high stability.

DETAILED DESCRIPTION OF THE INVENTION

As used herein, the term "non-aqueous" means the organic phase of thepresent invention comprises less than 50 parts by weight ("pbw"), morepreferably less than 30 pbw, even more preferably less than 10 pbw, andstill more preferably less than 1 pbw water per 100 pbw of the organicphase.

Suitable non-aqueous emulsions include both emulsions of a discontinuousorganic phase in a continuous silicone phase and emulsions of adiscontinuous silicone phase in a continuous organic liquid phase, withthe former being the more highly preferred embodiment of the presentinvention.

In a preferred embodiment, the nonaqueous emulsion of the presentinvention comprises, based on 100 parts by weight of the emulsion, from0.1 to 99.9 pbw, more preferably form 5 to 95 and even more preferablyfrom 20 to 80 pbw of the silicone phase, and from 0.1 to 99.9 pbw, morepreferably more preferably form 5 to 95 and even more preferably from 20to 80 pbw of the organic phase.

In a preferred embodiment, the silicone phase comprises from 0.005 to 30pbw, more preferably from 0.01 to 20 pbw, even more preferably from 0.5to 15 pbw of the silicone elastomer and from 70 to 99.995 pbw, morepreferably from 80 to 99.99 pbw, even more preferably from 85 to 99.95pbw of the low molecular weight silicone compound.

In a preferred embodiment, the non-aqueous silicone emulsion of thepresent invention comprises a silicone and a non-aqueous organichydroxylic solvent, wherein said non-aqueous emulsion comprises acontinuous non-aqueous phase.

1. Silicone Phase

i Silicone Elastomer

In a preferred embodiment, the silicone elastomer forms a crosslinkedthree dimensional network that does not dissolve in, but is capable ofbeing swollen by the low molecular weight silicone. The crosslinking maybe provided by molecular entanglements, for example, entanglement ofhighly branched silicone polymers or, more preferably, by covalentbonding. While not wishing to be bound by theory, it appears that theswollen silicone elastomer network serves to stabilize the emulsion ofthe present invention.

The amount of crosslinking present in the crosslinked silicone elastomernetwork may be characterized with respect to the degree of swellingexhibited by the network in the low molecular weight silicone fluid. Ina preferred embodiment, the crosslinked structure of the siliconeelastomer is effective to allow the network to be swollen by the lowmolecular weight silicone fluid from its original volume to a swollenvolume that is a factor of from 1.01 to 5000, more preferably from 2 to1000, and even more preferably from 5 to 500, times its original volume.

The silicone elastomer contains "D" structural units, and may optionallyinclude "T" structural units, or "Q" structural units, or both T and Qstructural units. The T and Q structural units provide branching sitesand potential crosslinking sites. Branching and crosslinking sites mayalso be provided by the R substituent groups bonded to silicon atoms ofeach of two or more of the siloxane chains of the silicone elastomer.

In addition to the selection of reactive substituent groups to providepossible crosslinking sites, substituent groups which are non-reactiveunder anticipated processing and use conditions may be selected tomodify the properties of the silicone elastomer by, for example,providing surfactant groups to promote formation of an emulsion with theorganic solvent, or enhancing the compatibility of the elastomer withorganic additives, such as, for example, fragrances, or modifying theaesthetic or sensory characteristics, for example, tactile properties or"feel", of the silicone phase of the present invention. Suitablesubstituent groups include, for example, H, hydroxyl, monovalent acyclichydrocarbon radicals, monovalent alicyclic hydrocarbon radicals,monovalent aromatic hydrocarbon radicals, ester radicals, thioesterradicals, amide radicals, polyester radicals, polythioester radicals,polyamide radicals ether radicals, polyether radicals.

As used herein, the terminology "acyclic hydrocarbon radical" means astraight chain or branched hydrocarbon radical, preferably containingfrom 2 to 50 carbon atoms per radical, which may be saturated orunsaturated and which may be optionally substituted or interrupted withone or more functional groups, such as, amino, carboxyl, cyano, hydroxy,halo, mercapto, mercaptocarbonyl, dihydroxyphosphinyl, oxo, oxy, alkoxy,aryl, aryloxy. Suitable monovalent acyclic hydrocarbon radicals include,for example, methyl, sec-butyl, tert-butyl, hexyl, cetyl, isostearyl,propenyl, butynyl, methoxy, hydroxypropyl, aminoethyl, cyanopropyl,carboxyethyl, chloropropyl, acrylo, methacrylo.

As used herein, the terminology "alicyclic hydrocarbon radical" means aradical containing one or more saturated hydrocarbon rings, preferablycontaining from 4 to 10 carbon atoms per ring, per radical which mayoptionally be substituted on one or more of the rings with one or morealkyl or alkylene groups, each preferably containing from 2 to 6 carbonatoms per group, or other functional groups and which, in the case oftwo or more rings, may be fused rings. Suitable monovalent alicyclichydrocarbon radicals include, for example, cyclohexyl, cyclooctyl.

As used herein, the term "aromatic hydrocarbon radical" means ahydrocarbon radical containing one or more aromatic rings per radical,which may optionally be substituted on the one or more aromatic ringswith one or more alkyl or alkylene groups, each preferably containingfrom 2 to 6 carbon atoms per group, or other functional groups andwhich, in the case of two or more rings, may be fused rings. Suitablemonovalent aromatic hydrocarbon radicals include, for example, phenyl,styryl, α-methylstyryl, naphthyl.

Suitable ester radicals include alkylcarbonyloxyalkylene radicals, suchas, for example, methycarbonyloxypropylene.

Suitable thioester radicals include alkylthiocarbonylalkylene radicals,such as, for example, methythiocarbonylpropylene.

Suitable amide radical include alkylamidoalkylene radicals, such as forexample, methylamidopropylene.

Suitable polyester radicals include, for example, those according to thestructural formula: ##STR1## wherein: R²¹ represents the residue of thediol or diol equivalent ("diol residue"),

R₂₂ represents the residue of the diacid or diacid equivalent (diacidresidue"),

a is an integer from 1 to 20;

R²³ is H, alkyl, hydroxalkyl, and each R²¹ and R²² is independently adivalent acyclic hydrocarbon radical, such as, for example, dimethylene,trimethylene, tetramethylene, hexamethylene and octamethylene, adivalent alicyclic hydrocarbon radical, such as, for example,2,2,4,4-tetramethyl-1,3-cyclobutylene, 1,4-cyclohexylene,cyclohexylene-1,4-dimethylene, 1,4-cyclooctylene, or a divalent aromatichydrocarbon radical, such as, for example, 1,2-phenylene, 1,3-phenylene,1,4-phenylene, 2,6-naphthalene, 2,7-phenathrylene, such as, for example,those polyester substituent groups disclosed in U.S. Pat. Nos.5,214,118, 3,778,458 and 4,945,147.

Suitable polythioester radicals and polyamide radicals include analogsof the above described polyester radicals, wherein the divalent oxygenatoms of the polyester radical is replaced by sulfur or nitrogen, suchas, for example, the polyamide radicals disclosed in U.S. Pat. Nos.5,274,065, and 5,437,813.

As used herein the term "polyether radical" means a monovalent groupaccording to the structural formula: ##STR2## wherein R³¹ is alkylene,R³² is H, alkyl, alkenyl, alkoxy, carboxy, hydroxyalkyl;

e and g are each independently integers of from 1 to 12; and

g and h are each independently integers of from 0 to 100; and

1≦g+h≦200.

Suitable silicone elastomers can be made by known synthetic techniques,such as, for example, addition polymerization, condensationpolymerization, free radical polymerization.

In a preferred embodiment, the silicone elastomer is made by an additionpolymerization reaction, more preferably, a hydrosilylation reaction.

In a highly preferred embodiment, the silicone elastomer is made by ahydrosilylation reaction between an alkenyl silicone precursor and ahydrogen silicone precursor. Generally, the alkenyl silicone precursorcompound will be an organosiloxane or organopolysiloxane having two ormore alkenyl groups per molecule on average and the hydrogen siliconeprecursor will be an organohydrogensiloxane having two or more siliconhydride groups per molecule on average. Such compounds are described ina multiplicity of U.S. patents particularly U.S. Pat. Nos. 5,506,289;5,674,966; 5,717,010; 5,571,853; and 5,529,837 herewith specificallyincorporated by reference. The alkenyl functionality and the hydridefunctionality may be combined into one molecule self-curing molecule orcompound as is taught in U.S. Pat. No. 5,698,654. In many embodimentsthe silicone elastomer comprises particles which may or may not befinely divided, of elastomer dispersed in a carrier oil, preferably asilicone oil.

In a very highly preferred embodiment, the non-aqueous emulsion of thepresent invention comprises:

the hydrosilylation addition product of

(1) a linear alkenyl stopped polyorganosiloxane having the formula:

    M.sup.vi.sub.a D.sub.x D.sup.vi.sub.y M.sub.2-a

where the subscript x is a number greater than 500 preferably greaterthan 600, more preferably greater than 700, and most preferably greaterthan 800, the subscript y is a number ranging from zero to about 20,preferably ranging from zero to about 10, more preferably ranging fromzero to about 5, and most preferably ranging from zero to about 4, thesubscript a is a number ranging from 0 to 2, subject to the limitationthat a+y is within the range of from 1 to about 20, preferably from oneto about 10, more preferably from about 1.5 to about 10, and mostpreferably from about 1.5 to about 6, with M^(vi) defined as:

    R.sup.1 R.sup.2 R.sup.3 SiO.sub.1/2

where R¹ is a monovalent unsaturated hydrocarbon radical having from twoto ten carbon atoms, preferably styryl, allyl and vinyl, more preferablyallyl and vinyl and most preferably vinyl and R² and R³ are eachindependently selected from the group of from one to fifty, carbon atommonovalent hydrocarbon radicals, more preferably from one to forty,carbon atom monovalent hydrocarbon radicals, even more preferably one totwenty carbon monovalent hydrocarbon radicals, still more preferablyfrom the group consisting of methyl, ethyl, propyl, iso-propyl, n-butyl,iso-butyl, sec-butyl, tert-buty, pentyl, hexyl, heptyl, phenyl, benzyl,and mesityl; and most preferably from the group consisting of methyl andphenyl with D defined as:

    R.sup.4 R.sup.5 SiO.sub.2/2

where R⁴ and R⁵ are each independently selected from the group of one toforty carbon atom monovalent hydrocarbon radicals, preferably one totwenty carbon monovalent hydrocarbon radicals, more preferably from thegroup consisting of methyl, ethyl, propyl, iso-propyl, n-butyl,iso-butyl, sec-butyl, tert-buty, pentyl, hexyl, heptyl, phenyl, benzyl,and mesityl; and most preferably from the group consisting of methyl andphenyl;

with D^(vi) defined as:

D^(vi) =R⁶ R⁷ SiO_(2/2) where R⁶ is a monovalent unsaturated hydrocarbonradical having from two to ten carbon atoms, preferably styryl, allyland vinyl, more preferably allyl and vinyl and most preferably vinyl andR⁷ is independently selected from the group of one to forty carbon atommonovalent hydrocarbon radicals, preferably one to twenty carbonmonovalent hydrocarbon radicals, more preferably from the groupconsisting of methyl, ethyl, propyl, iso-propyl, n-butyl, iso-butyl,sec-butyl, tert-buty, pentyl, hexyl, heptyl, phenyl, benzyl, andmesityl; and most preferably from the group consisting of methyl andphenyl and with M defined as M=R⁸ R⁹ R¹⁰ SiO_(1/2) with R⁸, R⁹, and R¹⁰each independently selected from the group of one to forty carbon atommonovalent hydrocarbon radicals, preferably one to twenty carbonmonovalent hydrocarbon radicals, more preferably from the groupconsisting of methyl, ethyl, propyl, iso-propyl, n-butyl, iso-butyl,sec-butyl, tert-buty, pentyl, hexyl, heptyl, phenyl, benzyl, andmesityl; and most preferably from the group consisting of methyl andphenyl and

(2) a resin having the formula:

    (M.sup.H.sub.w Q.sub.z).sub.j

where Q has the formula SiO_(4/2) and where M^(H) has the formula H_(b)R¹¹ _(3-b) SiO_(1/2) with the subscript b ranging from 1 to 3, where R¹¹is a one to forty carbon atom monovalent hydrocarbon radical, preferablya one to twenty carbon monovalent hydrocarbon radical, more preferablyselected from the group consisting of methyl, ethyl, propyl, iso-propyl,n-butyl, iso-butyl, sec-butyl, tert-buty, pentyl, hexyl, heptyl, phenyl,benzyl, and mesityl; and most preferably selected from the groupconsisting of methyl and phenyl with the subscripts w and z having aratio of 0.5 to 4.0 respectively, preferably 0.6 to 3.5, more preferably0.75 to 3.0, and most preferably 1.0 to 3.0; and the subscript j rangingfrom about 2.0 to about 100, preferably from about 2.0 to about 30, morepreferably from about 2.0 to about 10, and most preferably from about3.0 to about 5.0; and

(3) a low molecular weight silicone, wherein the mixture of lowmolecular weight silicone with the reaction product of (1) and (2) hasbeen subjected to shearing forces that affect the average particledistribution and the distribution has certain unique properties;

wherein the addition product of the linear alkenyl stoppedpolyorganosiloxane (1) and resin (2) dispersed in the low molecularweight silicone is emulsifiable with the organic liquid.

In a preferred embodiment, the hydrosilylation reaction is carried outin at least a portion of the low molecular weight silicone and in thepresence of a hydrosilylation catalyst selected from the group ofruthenium, osmium, rhodium, iridium, palladium and platinumhydrosilylation catalysts. Exemplary of such catalysts are thosedescribed in U.S. Pat. Nos. 2,823,218; 3,159,601; 3,159,662; and3,775,452.

ii. Low molecular weight silicone fluid

The low molecular weight silicone fluid is an organosilicon compoundhaving a viscosity of below about 1,000 centistokes, preferably belowabout 500 centistokes, more preferably below about 250 centistokes, andmost preferably below 100 centistokes, at 25° C. Thus low molecularweight cyclic silicones such as D₃, D₄, D₅, and D₆ (i.e. D_(f) where thesubscript f ranges from 3 to 6) where D is as previously defined with R⁴and R⁵ preferably methyl as well as low molecular weight linearsilicones having the formula

    M'D'.sub.i M'

where the substituents on D' are independently selected from the samesubstituents as previously defined for D and M' has the formula

    R.sup.12 R.sup.13 R.sup.14 SiO.sub.1/2

where R¹², R¹³ and R¹⁴ are each independently selected from the group ofone to forty carbon atom monovalent hydrocarbon radicals, preferably oneto twenty carbon monovalent hydrocarbon radicals, more preferably fromthe group consisting of methyl, ethyl, propyl, iso-propyl, n-butyl,iso-butyl, sec-butyl, tert-buty, pentyl, hexyl, heptyl, phenyl, styryl,α-methyl styryl, benzyl, and mesityl; and most preferably from the groupconsisting of methyl and phenyl; and the subscript i ranges from 0 toabout 300, preferably from 0 to about 100, more preferably from 0 toabout 50, and most preferably from 0 to about 20 are such volatile,silicones. Preferably component (3) is a low molecular weight silicone.

iii. Preferred method for making silicone phase

The materials used to prepare the gels of the present invention havebeen defined in terms of formulas that recite structural elements M, D,T and Q within the definitions commonly accepted in the practice ofsilicone chemistry. As individual molecules, or as pure compounds, thesubscripts of these formulas can assume only integral values (includingzero where appropriate). As complex mixtures of compounds, each of whichindividually satisfies the molecular definition, the subscripts indescribing the mixture will assume non-integral values (including zerowhere appropriate). However, those non-integral values for a givensubscript will still range between the upper limit and the lower limitsof the range for that particular subscript when integral values arestipulated. Thus, for example in the pure compound description ofcomponent (1), the subscript a may have the values 0, 1 or 2. As amixture of compounds, component (1) will have an average value for thesubscript a that is dependent on the number of individual molecularspecies having a value for the subscript a that is equal to 0, 1, and 2.The same explanation holds for components (2) and (3).

Thus, the average subscripts for component (1), when component (1) is avinyl functionalized silicone as the specific alkenyl functionalizationand is a mixture of various vinyl containing compounds, as defined, willspan a range of vinyl equivalent weights ranging from about 1,500 toabout 150,000, preferably from about 4,500 to about 110,000, morepreferably from about 10,000 to about 70,000, and most preferably fromabout 15,000 to about 45,000. It is to be noted that these equivalentweights are specific equivalent weights for vinyl substitution,substitution with other olefinic substituents would generate a differentbut comparable range of equivalent weights. Likewise, the averagesubscripts for component (2) as a mixture, as defined, will span a rangeof hydride equivalent weights ranging from about 80 to about 190,preferably from about 82 to about 170, more preferably from about 85 toabout 150, and most preferably from about 87 to about 130.

Further it is desirable that the alkenyl functionality present incomponent (1) ranges on average of from about 2 to about 20 alkenylgroups per molecule, preferably from about 1 to about 10 alkenyl groupsper molecule, more preferably from about 1.5 to about 10 alkenyl groupsper molecule, and most preferably from about 1.5 to about 6 alkenylgroups per molecule. Additionally, it is desirable that the hydridefunctionality present in component (2) ranges on average of from about 2to 400 SiH groups per molecule, preferably from about 8 to about 100 SiHgroups per molecule, more preferably from about 8 to about 50 SiH groupsper molecule, and most preferably from about 8 to about 20 SiH groupsper molecule.

Components (1) and (2) (as pure compounds or mixtures) are catalyticallyreacted together in the presence of component (3) to produce a gelhaving a polymer content that is approximately from about 5 to about 75weight percent crosslinked polymer, preferably from about 10 to about 60weight percent crosslinked polymer, more preferably about 15 to about 40weight percent crosslinked polymer, and most preferably about 20 toabout 35 weight percent crosslinked polymer with the balance being thevolatile, low molecular weight silicone oil. Once this initiallyproduced gel is prepared, it is mixed with an additional quantity of avolatile, low molecular weight silicone, i.e. additional component (3)which is possibly different from the component (3) used to prepare theinitially produced gel, and subjected to mixing or shearing forces toproduce a uniform liquid gel that is from about 1 to about 25 weightpercent crosslinked polymer, preferably from about 2 to about 20 weightpercent crosslinked polymer, more preferably from about 3 to about 15weight percent crosslinked polymer, and most preferably from about 3 toabout 10 weight percent crosslinked polymer with the balance being thevolatile, low molecular weight silicone oils, component (3) or a mixtureof compounds satisfying the definition of component (3).

The gel initially produced is sufficiently viscous that liquid flow isnot ordinarily observable. As a crosslinked polymeric material, the gelinitially produced, having 25 weight percent crosslinked polymernetwork, has a Durometer hardness number, ASTM D-2240-91,of at least 5,preferably of at least 7, more preferably of at least 10 and mostpreferably of at least 15. ASTM test numbers for the Durometer hardnesstest are indicative of a material sufficiently resistant to flow that itmay fairly be characterized as a solid.

In recent years, the personal care industry has found that the use of avariety of silicone polymers ranging from very low to very highmolecular weight can provide improved product flow and a smooth,non-greasy feel in a wide range of applications. So for example,silicone polymers have been used in formulations forantiperspirant/deodorants, skin lotions, creams, hair care, cosmeticsand the like. While these silicone polymers provide the desiredperformance characteristics to personal care products, they havetraditionally required a delivery system that includes non-siliconethickening agents. These non-silicone thickening agents are generallyundesirable as they have a negative impact on the desired silicone feel.

Recent technology that teaches the use of crosslinked silicone polymersfor thickening agents fails to recognize the need to generate the uniqueand desirable distribution of crosslinked silicone polymer particlesthat create superior performance characteristics including the smoothsilky feel and high viscosity for optimal thickening effects. Thistechnology does not adequately define a process for generating the mosthighly desired distribution of these particles. In addition, some of theprocessing methods suggested by this technology are limited to only asmall range of crosslinked silicone polymer that can be useful in theinstant invention. Thus as the nature of the crosslinked siliconepolymer changes to provide for the desirable, more efficient use ofpolymer material, the suggested shearing methods using low levels ofcompression (colloid mills and the like), mechanical cutting shear(rotor/stator mills) or fracture (hammer mills) fail to provide thedesired crosslinked silicone polymer particles of the required size anddistribution. Further, they fail to define a method for processing thecrosslinked silicone polymer in an economical manner.

Surprisingly a process has been discovered for providing a thickener forcarrier silicone oil comprising the use of silicone particles having aunique distribution of particle sizes. Further, it has been discoveredthat the use of high flow induced shear and particle elongation inaddition to providing an economical method for processing crosslinkedsilicone polymers, also generates a unique and highly desirable particlesize distribution that provides the desired smooth, silky feel whilemaintaining high viscosity and thickening properties. Further thismethod of processing is applicable to the entire range of desirablecrosslinked silicone polymers.

While some of the physical properties of the thickening agent aredetermined by the chemical structure of the crosslinked siliconepolymer, the particle size and distribution are key to the highlydesirable thickening (viscosity) and feel properties of the product. Theefficient thickening behavior is the result of having large particlesizes present to increase the fluid viscosity. The size of the largeparticles is limited by the need to avoid particle so large that theyform visible balls of gel during application. The superior feel is theresult of generating smaller particles that improve lubricity duringspreading on the skin. If the crosslinked silicone polymer is degradedto too small particles or to homogeneous fluids, they become undesirablyheavy or greasy in feel. Thus preparing an efficient thickening agentwith the superior feel requires the ability to generate a widedistribution of particles.

Surprisingly, the use of flow induced shear and particle elongationparticularly at high stress levels provides a unique distribution ofparticle sizes when used to process crosslinked silicone polymers. Whereas the normal expectation is to find a monomodal or possibly bimodaldistribution of particle sizes when employing stress to break downparticles, it is found that particularly high flow induced shear andparticle elongation produce multiple distributions of particle sizes.

Earlier experiments have shown that the particles prepared in thisinvention are not fully swollen in material as dilute as five percentelastomer content and 95% cyclic siloxanes. However, if the elastomer isfurther diluted below elastomer contents of about three percent, theparticle swells to its full extent. Thus the particle sizes reported inthis invention demonstrate fully extended particles, while those used inmost applications are of proportionally smaller actual volume dependingon the available solvent. Since for a given particle composition it ispossible to measure how much additional solvent may be absorbed, it ispossible to back calculate the particle size for any given concentrationonce the full extended particle size is known. Further, it is within thescope of this invention to prepare smaller particles at a higherelastomer concentration and then swell them at a later time withadditional solvent to achieve a larger particle size.

For the product of this invention, the particle size distributioncomprises a multiple series of individual and often overlapping particlesize populations. Taken together they provide a broad distribution ofboth large and small particles that impart both high efficiency andviscosity as well as a good feel and lubricity. The individual particlesize populations generally fit a log normal particle size distributionand as measured at full range from an average of about 10 microns to anaverage of about 600 microns. When for a specific application theparticles are not fully swollen, the population of particle sizes, i.e.the particle size distribution, will cover proportionally smaller sizesand with a shift to ranges over lower particle sizes. The particle sizedistribution comprises a series of multiple, identifiable particlepopulations ranging from less than about 1 microns on swelling to about600 microns after swelling. It is preferable for the average particlesize range when measured in a fully swollen state to cover from about 1to about 500 microns, more preferably to include about 1 to about 400microns and most preferably to include about 1 to about 300 micronsafter solvent swelling.

The compositions of the present invention are characterized by beingdispersions of an organic polymeric elastomer, preferably a siliconeelastomer, in a suitable solvent and having a particle size distributioncharacterized by the presence of three local maxima in the particle sizedistribution: 1) a local maximum ranging from about 21 to about 26microns, 2) a local maximum ranging from about 33 to about 38 microns,and 3) a local maximum ranging from about 50 to 60 microns. As localmaxima, these three local maxima appear as identifiable spikes in a plotof population versus particle diameter. It is to be emphasized that thecompositions of the present invention may possess more than these threelocal maxima in a plot of population versus particle size, but thecompositions of the present invention always possess these three localmaxima. Depending on other features of the particle size distribution,the subjective properties of the composition vary from a so-called stiffcreamy feel when the distribution is skewed to higher particle diametersto a light creamy feel when the distribution is centered around thesethree local maxima to a heavy greasy feel when the distribution isskewed to lower particle diameters. These numbers are specific to theinstrumental method of analyzing the particle size distribution,specifically using a Malvern Mastersizer fitted with a 300 mm lens.

The process for making suitable crosslinked silicone polymer particlesfor use in the current application involves the preparation of acrosslinked silicone polymer, often in a low molecular weight siliconefluid. The material may then be further swollen with additional solventeither the same or different than that used in making the crosslinkedsilicone polymer. The crosslinked silicone polymer is then subjected toforce to break it into small particles often in the presence ofadditional silicone fluid. It is a discovery of this invention that thesuperior method of breaking the polymer into small particles is throughhigh flow induced shear. In this method, the slurry is first diluted,including the crosslinked silicone polymer and any additionally desiredsolvent, and then forced through an orifice under pressure generatingflow induced shear and particle elongation. In this method, the flowinduced shear and particle elongation occur both as the material passesthrough the orifice and in the entry region to the orifice. Althoughsome material may be cleaved by hitting the edge of the orifice, it isthis flow induced shear and particle elongation that ultimately tearsthe crosslinked silicone polymer apart and creates small particles.

The magnitude and profile of the flow induced shear in this process iscontrolled by several parameters including the pressure, orificegeometry and fluid viscosity which in part reflects the temperature,flow and shear characteristics of the fluid. Pressure may be defined asthe pressure drop across the orifice. Increasing pressure drop increasesthe flow induced shear such that the crosslinked silicone polymer ismore rapidly torn into the desired particle sizes and with a wider, moredesirable distribution of particle sizes. Generally, high flow inducedshear is associated with higher pressure drops for a particular orificegeometry and fluid viscosity.

The orifice geometry at a given pressure drop also determines the natureof high flow induced shear. Orifice geometry is a very flexiblecharacteristic with a variety of shapes and sizes. Thus for example, anorifice might have an opening shape that is round, ovoid, rectangular orannular. Such orifices may be completely open or contain a pin or otherobstruction at the opening. There may be one opening or many of the sameor different geometries. In general as the orifice gets larger at thesame pressure and fluid viscosity, the distribution of particle sizesbecomes wider and more desirable. Similarly the length of the pathtraveled by the fluid may be long or short, straight or bent. In generalas the length of the orifice becomes shorter, the flow induced shearincreases and smaller more widely distributed particles are generated.The orifice size also influences flow induce shear in the entry regionto the orifice. Thus as the ratio increases such that the material flowsfrom a larger tube to a smaller orifice the particle size distributionis increased.

Fluid viscosity also determines the flow induced shear. As the viscosityof the fluid increases, the flow induced shear increases with theattendant desirable results. Viscosity will be influenced by thetemperature, a lower more constant temperature giving higher viscosityis desirable. Similarly, materials exhibiting shear thinning, as somesilicones are known to do, will have a lower flow induced shear in theorifice, thus increasing the particle size and narrowing thedistribution. While the viscosity of the initial slurry of elastomer fedto the process may be difficult to measure, after processing theviscosity can be measured and for the first several passes through theprocess the viscosity of the elastomer dispersion increases. Because thematerial being processed is a dispersion or suspension of elastomerparticles in a solvent, viscosity may be affected by a consideration ofthe so-called solids level. As the solids level is increased, i.e. theamount of solvent present being progressively reduced, resistance toflow increases, which can sometimes be measured as an increase inviscosity.

Taken together, these parameters are the major factors in determiningflow induced shear. Depending upon a particular environment, any one ormore of these three may be the dominant, i.e. most critical factor(s),in deciding the actual flow induced shear. High dynamic shear is thatwhich is sufficient to break down the crosslinked particles to thedesired size and distribution. In some instances this is accomplished ina single pass through the orifice, or alternatively a few to severalpasses may be required to achieve the desired particle size. In generalfewer passes and wider particle size distribution are the more desiredeconomic and performance results coming from high flow induced shear.

Flow induced particle elongation occurs as the crosslinked siliconepolymer converges under pressure as it is forced to flow toward theorifice, flowing from a large diameter environment to the small diameteropening. As the particle travels through this region, it is elongatedand smaller particles generated. The critical factors include pressure,fluid viscosity and the ratio of the cross sectional areas of the feedchamber to orifice. As the pressure is increased the particle elongationis increased and more efficient particle size breakage is achieved.Similarly, as the viscosity of the fluid is increased, the particleelongation is increased. As the ratio of the cross sectional areas ofthe feed chamber to the orifice is increased, the particle elongation isincreased. In general as the particle elongation increases theefficiency in breaking down particles increases requiring fewer passes.

The pressure range desirable for sufficient flow induced shear andparticle elongation is above 500 psi. Preferably it is above 1000 psi,more preferably over 1500 psi and most preferably over 2000 psi . Theviscosity should be above 500 ctks. Preferably is should be over 750ctks more preferably over 1000 ctks and most preferably over 5000 ctks.The orifice size is limited by the ability of the pumping system tomaintain sufficient pressure. As a practical matter it is desirable tohave an orifice size of less than 0.5 square inches, preferably lessthan 0.1 square inches, more preferably less than 0.05 sq. in, and mostpreferably less than 0.01 sq. inch.

The interaction of all of these operating variables combine to produce aprocess where the elastomer dispersion is reduced in average particlesize and the unique particle size distribution is produced. Generallyunless the elastomer dispersion is processed at a very high pressuredrop, conversion to a desirable composition is not achieved in a singlepass. There is thus a correlation between the applied pressure drop andthe number of passes through the processing equipment that the elastomerdispersion must be subjected to in order to convert the material to thedesired composition. This is reflected by the following dimensionlesscorrelation equation that determines the number of passes, N_(p)necessary to produce acceptable material for a given pressure drop,P_(d) :

    N.sub.p =82,799P.sub.d.sup.(-1.1696)

To some extent this equation is arbitrary and varies as the definitionof what constitutes acceptable material. Material possessing a particlesize distribution characterized by three peaks or three local maxima inthe particle size distribution: 1) a local maximum ranging from about 21to about 26 microns, 2) a local maximum ranging from about 33 to about38 microns, and 3) a local maximum ranging from about 50 to 60 micronsconstitutes material that is acceptable.

Further, it is possible to generate a dimensionless correlation whichcorrelates the resulting average particle size (as determined by aMalvern Mastersizer™), S_(p) (avg.), with the pressure drop, P_(d),orifice cross-sectional area, O_(a), and the number of passes, N_(p).

    S.sub.p (avg.)=K+C.sub.1 P.sub.d +C.sub.2 O.sub.a +C.sub.3 N.sub.p,

where K is an intercept, and the various C_(i) 's are coefficientsassociated with the indicated variable, i.e. C₁ is the pressure dropcoefficient, C₂ is the orifice cross-sectional area coefficient, and C₃is the number of passes coefficient. The various operating ranges aredefined in the following tables:

                  TABLE A                                                         ______________________________________                                        Operating Ranges                                                                  Parameter Minimum (from about)                                                                        Maximum (to about)                                ______________________________________                                        P.sub.d   500           35000                                                   O.sub.a 0.5 0.0001                                                            N.sub.P 1 100                                                                 S.sub.p (avg.) 585 16                                                         K 639 639                                                                     C.sub.1 -0.026 0.026                                                          C.sub.2 -61 -61                                                               C.sub.3 2.87 2.87                                                           ______________________________________                                    

                  TABLE B                                                         ______________________________________                                        Preferred Operating Ranges                                                        Parameter Minimum (from about)                                                                        Maximum (to about)                                ______________________________________                                        P.sub.d   1000          30000                                                   O.sub.a 0.1 0.002                                                             N.sub.p 1 50                                                                  S.sub.p (avg.) 3 610                                                          K 639 639                                                                     C.sub.1 -0.026 -0.026                                                         C.sub.2 -61 -61                                                               C.sub.3 2.87 2.87                                                           ______________________________________                                    

                  TABLE C                                                         ______________________________________                                        More Preferred Operating Ranges                                                   Parameter Minimum (from about)                                                                        Maximum (to about)                                ______________________________________                                        P.sub.d   1500          27500                                                   O.sub.a 0.005 0.0003                                                          N.sub.p 1 30                                                                  S.sub.p (avg.) 10 603                                                         K 639 639                                                                     C.sub.1 -0.026 -0.026                                                         C.sub.2 -61 -61                                                               C.sub.3 2.87 2.87                                                           ______________________________________                                    

                  TABLE D                                                         ______________________________________                                        Most Preferred Operating Ranges                                                   Parameter Minimum (from about)                                                                        Maximum (to about)                                ______________________________________                                        P.sub.d   2000          25000                                                   O.sub.a 0.01 0.0005                                                           N.sub.p 1 10                                                                  S.sub.p (avg.) 18 589                                                         K 639 639                                                                     C.sub.1 -0.026 -0.026                                                         C.sub.2 -61 -61                                                               C.sub.3 2.87 2.87                                                           ______________________________________                                    

Because the number of passes, N_(p), correlates with the pressure drop,P_(d), the equation for the number of passes may be substituted into theaverage particle size equation. This mathematical substitutionunderscores the strong pressure drop dependence of the process. Simplystated, the process of the present invention (to yield the compositionof the present invention) is a process where an elastomer dispersion issubjected to a pressure and passed through an orifice at a specifiedpressure drop wherein the average particle size is reduced and theparticle size distribution yields certain specified local maxima. Anyprocess that achieves this conversion by means of a pressure drop and anorifice is a process of the present invention. Applicants note that thepressure drop as used herein has the dimensions of pounds per squareinch (psi.), the orifice cross-sectional area has the dimensions ofsquare inches (sq. in. or in.²), and particle sizes or average particlesize has the dimension of microns. As the orifice size decreases thepressure must be increased to maintain throughput. For this reason, asmaller orifice size is listed under the column heading "maximum" indescribing the ranges, because smaller orifice size and increasedpressure create the same global effect.

Finally, it should be emphasized that the intercept and coefficients inthe process variable equation may change depending on the specificmachine used. The data presented herein represent the results of acorrelation on a few selected machines are thus illustrative rather thanconstituting a definition or limitation. Thus while the processvariables are fairly precisely defined, the intercept, K, and thecoefficients C₁, C₂, and C₃ are more likely to depart from the valuesreported herein than would the actual process variables. Irrespective ofthe actual machine and the actual values of the intercept and thesecoefficients in a process variable correlation, any processaccomplishing the conversion of particle size to that defined herein isintended to be covered by the appended claims.

The generation of the desired particle size is in part determined by theswelling of the particles before application of the flow induced shearand particle elongation. As the particle swells with solvent, internalstress is developed which lowers the level of shear and particleelongation required to tear apart the particle. Thus more swelling orlower crosslinked silicone polymer concentration in the slurry beingprocessed increases the internal stress and makes the process moreefficient. It is desirable to dilute to a crosslinked polymerconcentration of less than 60% by weight solids. It is preferable toswell and dilute the crosslinked silicone polymer to less than 50% byweight solids, more preferable to swell the crosslinked polymer to lessthan 40% by weight solids and most preferable to dilute the crosslinkedpolymer to less than 30% by weight solids content.

The resistance to flow of the initially produced gel is overcome by highspeed mixing or shearing wherein the resulting composition or mixture isa uniform liquid and has a viscosity ranging from about 500 to about150,000 centistokes at 25° C., more preferably the resulting viscosityof the composition or mixture is from about 1,000 to about 100,000centistokes at 25° C., and most preferably the resulting viscosity ofthe composition or mixture is from about 10,000 to about 60,000centistokes at 25° C. By shearing, Applicants mean the imposition of aforce upon the composition where the mixture is treated using a two rollmill, a colloid mill, a Gaulin homogenizer, a Sonolator, Ross™ mixer,Aviston™ mixer, Microfluidizer, etc. The elastomer dispersions processedby the process of the present invention are comprised of an elastomergel and a low molecular weight silicone. The process of the presentinvention used to achieve the composition of the present invention maybe applied to an elastomer dispersion or a dispersion of a gel or a gel.Subjecting these compositions to a shearing force produces a componentsuitable for use in personal care or cosmetic applications that has animproved spreadability and an improved substance or feel because of thepresence of the composition of the present invention possessing a uniqueparticle size distribution.

The silicone phase may optionally include a minor amount of organiccomponents that are miscible with the silicone phase and immisible orpartially miscible with the organic phase, such as, for example,fragrances or oils.

The Organic liquid

The organic liquid may be any organic compound that is in the liquidstate at room temperature, for example, about 25° C., and about oneatmosphere pressure, that is substantially inert to the silicone phase,that is, does not undergo a chemical reaction with any of the componentsof the silicone phase, under the anticipated conditions of processingand use and that is suitable for use in the intended end-useapplication, such as, for example, a cosmetic composition, to beprepared from the non-aqueous emulsion of the present invention.

In a preferred embodiment, the organic liquid is a polar liquid thatexhibits a dipole moment of from 0.9 to 4.5.

In a highly preferred embodiment, the organic liquid is a organichydroxylic liquid, containing for example, one or more of alcohols,glycols, polyhydric alcohols and polymeric glycols. More preferably, theorganic liquid is selected from of alcohols including polyhydricalcohols, glycols, including polymeric glycols, and mixtures thereof.Preferably, the polar organic liquid contains an (C₁ -C₁₂)alcohol, suchas for example, ethanol, propyl alcohol and iso-propyl alcohol, a (C₂-C₁₂)glycol, such as for example, propylene glycol, dipropylene glycol,tripropylene glycol, butylene glycol, iso-butylene glycol, 2- andmethyl-3-propane diol, a polyhydric alcohol, such as for example,glycerin erythritol and sorbitol, or a polymeric glycol, such as forexample, polyethylene glycol, polypropylene glycol mono alkyl ethers andpolyoxyalkylene copolymers. In a highly preferred embodiment, theorganic liquid is selected from ethanol, propyl alcohol, iso-propylalcohol, propylene glycol, dipropylene glycol, tripropylene glycol,butylene glycol, iso-butylene glycol, 2-methyl-3-propane diol, glycerin,erythritol sorbitol, polyethylene glycol, polypropylene glycol monoalkyl ethers, polyoxyalkylene copolymers.

Emulsifying agent

In a preferred embodiment, the emulsion of the present inventioncomprises one or more emulsifying agents. Suitable emulsifying agentsuseful in preparing the emulsions of the present include, for example,silicone-containing emulsifying agents, emulsifying agents derived fromsorbitan compounds and emulsifying agents derived from fatty alcoholsand polymeric emulsifiers, more preferably the emulsifying agent isselected from the group consisting of fatty acid esters, sorbitansesquioleate, sorbitan oleate, sorbitan isostearate, polyglyceryl-3oleate, alkoxylated alcohols such as laureth-4, laureth-7, deceth-12,steareth-10, hydroxylated or alkoxylated derivatives of siliconecompounds such as dimethicone copolyol, cetyl dimethicone copolyol, andlauryl methicone copolyol, glyceryl esters such aspolyglyceryl4-isostearyl polymeric emulsifiers, such asalkylpolyglucosides and mixtures thereof; and most preferably theemulsifying agent is dimethicone coployol which may or may not bedispersed in a silicone oil or cyclomethicone diluent. In a preferredembodiment, the dimethicone copolyol emulsifier has limited solubilityin the silicone phase to be emulsified.

Making the non-aqueous emulsion

The silicone phase and the organic liquid are mixed to form thenon-aqueous emulsion of the present invention. In a preferredembodiment, the organic liquid is slowly added to the silicone phasewhile subjecting the combined organic liquid and silicone phase to lowshear mixing, such as, for example, in a mixing tank equipped with apropeller-type stirrer, and then the mixture so formed is homogenized,for example, in a Sonolator apparatus, a Gaullen homogenizer or a highshear mixer, such as an Eppenbach Mixer, to form the emulsion. In a morehighly preferred embodiment, an emulsifying agent is combined with thesilicone phase prior to adding the organic liquid to the silicone phase.

3. Personal care compositions

The personal care applications where the emulsions of the presentinvention may be employed include, but are not limited to, deodorants,antiperspirants, skin care products, hair care products such asshampoos, mousses, styling gels, protective creams, such as sunscreen,and color cosmetics such as lip products or lipsticks, foundations,blushes, makeup, and mascara; and other cosmetic formulations wheresilicone components have been added.

Suitable personal care compositions are made by combining one or more ofthe above components with the emulsion of the present invention. Thecomponents may be added before or after formation of the non-aqueousemulsion In a preferred embodiment, any such desired components areadded to the silicone phase or to the organic liquid prior to mixing thesilicone phase with the organic liquid to form the non-aqueous emulsion.Similarly, the compositions of the present invention also have utilityas drug delivery systems for topical application of medicinalcompositions that are to be applied to the skin.

In a preferred embodiment, a personal care composition comprisesnon-aqueous emulsion of the present invention and one or morewater-sensitive dermatological active agents or cosmetic active agents,such as for example, ascorbic acid or an enzyme, particularly aprotease, such as for example, enzyme sold under the trade nameSUBTILISIN SP 544 by Novo Nordisk or the enzyme sold under the tradename LYSOVEG by Laboratoires Serobiologiques de Nancy.

In a preferred embodiment, a deodorant composition comprises one or moreanti-microbial agents, such as, for example, Triclosan, and thenon-aqueous silicone emulsion of the present invention

In a preferred embodiment, an antiperspirant composition comprises oneor more active antiperspirant agents, such as, for example, aluminumhalides, aluminum hydroxyhalides, for example, aluminum chlorohydrate,and complexes or mixtures thereof with zirconyl oxyhalides and zirconylhydroxyhalides, such as for example, aluminum-zirconium chlorohydrate,and the non-aqueous silicone emulsion of the present invention.

In a preferred embodiment, a skin cream composition comprises anemollient, such as, for example, triglyceride esters, wax esters, alkylor alkenyl esters of fatty acids or polyhydric alcohol esters, and thenon-aqueous silicone emulsion of the present invention.

In a preferred embodiment, a sunscreen composition comprises one or moreabsorbing or blocking agents for ultraviolet radiation, such as, forexample, titanium dioxide, zinc oxide, octylcrylene, octyl methoxycinnamate, avobenzone oxybenzone sunscreens and p-aminobenzoic acid, andthe non-aqueous silicone emulsion of the present invention.

These cosmetic compositions will in all probability also contain othermaterials designed to improve appearance or functionality of thecomposition and as such cosmetic compositions prepared with thecompositions of the present invention may additionally comprise suchknow components as, for example, emollients, pigments, colorants,fragrances, preservatives, exfoliants, hormones, enzymes, medicinalcompounds, anti-microbial agents, anti-fungal agents, vitamins, salts,absorbing agents for ultraviolet (UV) radiation and botanical extracts,as well as thickening agents, such as, for example, fumed silica orhydrated silica, and clays, such as, for example, bentonite.

The respective disclosures of all United States patents referencedherein are hereby incorporated herein by reference.

EXPERIMENTAL EXAMPLE 1

Preparation of Crosslinked Silicone Polymers in Volatile, Low MolecularWeight Silicone Oil

The crosslinked silicone polymers were prepared by mixing a given silylhydride species, a given vinyl species, and a volatile low molecularweight silicone oil in a reaction vessel and mixing. To such a mixture astandard hydrosilylation catalyst was added. Hydrosilylation in thepresence of platinum catalysts is described in U.S. Pat. Nos. 3,159,601;3,159,662; 3,220,972; 3,715,334; 3,775,452; and 3,814,730 herewith andhereby incorporated by reference. The mixture containing thehydrosilylation catalyst was heated and allowed to react at a giventemperature. Thus, for example, 1.11 grams of (M^(H) ₂ Q)₄, w=2, z=1,and j=4; 250 g of a vinyl terminated siloxane having an equivalentweight of 33,750 grams/equivalent vinyl, and 650 g ofoctamethylcyclotetrasiloxane were added to a dough mixer and stirred.100 g of 0.11% platinum catalyst in octamethylcyclotetrasiloxane wasadded. The reaction was stirred and heated to 80° C. for two hours. Thereaction was cooled and the product was isolated. Following this generalprocedure compositions A through T were prepared. The vinyl siloxane wasvaried through these preparations:

1) divinyl siloxane (A) is M^(Vi) D_(x) M^(Vi) where M^(Vi) is R¹ R² R³SiO_(1/2) where R¹ is (CH₂ ═CH) and R² and R³ are each independentlyCH₃, and D is R⁴ R⁵ SiO_(2/2) where R⁴ and R⁵ are each independentlyCH₃, with x varied from approximately 450 to approximately 1250;

2) monovinyl siloxane (B) is M^(Vi) D_(y) M where M^(Vi) is R¹ R² R³SiO_(1/2) where R¹ is (CH₂ ═CH) and R² and R³ are each independentlyCH₃, D is R⁴ R⁵ SiO_(2/2) where R⁴ and R⁵ are each independently CH₃,with y approximately equal to 200 and M is R⁸ R⁹ R¹⁰ SiO_(1/2) with R⁸,R⁹, and R¹⁰ each independently CH₃ ; and

3) pentavinyl siloxane (C) is MD_(i) D^(Vi) _(k) M where M is R⁸ R⁹ R¹⁰SiO_(1/2) with R⁸, R⁹, and R¹⁰ each independently CH₃, D is R⁴ R⁵SiO_(2/2) where R⁴ and R⁵ are each independently CH₃, with iapproximately equal to 200, and D^(vi) defined as: D^(vi) =R⁶ R⁷SiO_(2/2) where R⁶ is (CH₂ ═CH) and R⁷ is independently CH₃, with kapproximately equal to 5.

                  TABLE 1                                                         ______________________________________                                        Preparation of Crosslinked Polymeric Siloxane in Volatile, Low                  Molecular Weight Silicone Oil: (M.sup.H.sub.2 Q).sub.4 Resin Reacted        with Divinyl                                                                    Terminated Siloxane (A)                                                                                        Volatile,                                        Low Mol.                                                                   Si--H to Si- Divinyl  Wt.                                                     Vinyl Siloxane Polymer, Silicone, Platinum,                                  Comp'n Ratio A, mol. wt. wt. % wt. % ppm                                    ______________________________________                                        A     0.7/1.0   66800     25     75     10                                      B 0.9/1.0 66800 25 75 10                                                      C 1.0/1.0 66800 25 75 10                                                      D 1.1/1.0 66800 25 75 10                                                      E 1.3/1.0 66800 25 75 10                                                      F 1.5/1.0 66800 25 75 10                                                      G 1.58/1.0  66800 25 75 10                                                    H 1.3/1.0 33500 25 75 10                                                      I 1.3/1.0 92700 25 75 10                                                      J 1.3/1.0 66800 25  75* 10                                                    U 1.3/1.0 66800 50 50  5                                                      V 1.3/1.0 66800 15 85  5                                                    ______________________________________                                         Note:                                                                         *With the exception of preparation J which utilized D5                        (decamethylcyclopentasiloxane) all the other preparations utilized D4         (octamethylcyclotetrasiloxane).                                          

Preparations A through G study variations in the hydride to vinyl ratioof the hydrosilylation reaction. Preparations E, H and I studyvariations in the molecular weight of the vinyl component of thehydrosilylation reaction. Preparations E and J study variations in thevolatile, low molecular weight silicone oil.

The following preparations utilized a mixture of vinyl siloxanecompounds, divinyl siloxane A and monovinyl siloxane B, in contrast tothose preparations presented in Table 1 which utilized only one vinylsiloxane compound, divinyl siloxane A.

                  TABLE 2                                                         ______________________________________                                        Preparation of Crosslinked Polymeric Siloxane in Volatile, Low                  Molecular Weight Silicone Oil: (M.sup.H.sub.2 Q).sub.4 Resin Reacted        with Mixed                                                                      Divinyl Terminated Siloxane (A) and Monovinyl Siloxane (B)                                    Divinyl                                                                             Mono-            Volatile,                               Si--H Silo- vinyl   Low                                                       to xane Siloxane  Poly- Mol. Wt. Plati-                                       Si-vinyl A, mol. B, mol.  mer, Silicone, num,                                Comp'n Ratio wt. wt. A/B wt. % wt. % ppm                                    ______________________________________                                        K     1.3/1.0 66800   15900  90/10                                                                              25   75     10                                L 1.3/1.0 66800 15900 80/20 25 75 10                                          M 1.3/1.0 66800 15900 70/30 25 75 10                                          N 1.3/1.0 66800 15900 60/40 25 75 10                                          O 1.3/1.0 66800 15900 50/50 25 75 10                                          P 1.1/1.0 66800 15900 90/10 25 75 10                                          Q 1.1/1.0 66800 15900 70/30 25 75 10                                          R 1.1/1.0 66800 15900 50/50 25 75 10                                        ______________________________________                                    

Preparations K through O vary the ratio of divinyl siloxane A tomono-vinyl siloxane B at a constant hydride to vinyl ratio. PreparationsP through R again vary the ratio of divinyl siloxane A to mono-vinylsiloxane B but at a different constant hydride to vinyl ratio from thatin K through O.

The following preparations utilized a mixture of vinyl siloxanecompounds, divinyl siloxane A and pentavinyl siloxane C, in contrast tothose preparations presented in Table 1 which utilized only one vinylsiloxane compound, divinyl siloxane A.

                  TABLE 3                                                         ______________________________________                                        Preparation of Crosslinked Polymeric Siloxane inn Volatile, Low                 Molecular Weight Silicone Oil: (M.sup.H.sub.2 Q).sub.4 Resin Reacted        with Mixed                                                                      Divinyl Terminated Siloxane (A) and Pentavinyl Siloxane (C)                           Si--H   Divinyl                                                                             Penta-           Volatile,                               to Silo- vinyl   Low                                                          Si- xane Siloxane  Poly- Mol. Wt. Plati-                                      Vinyl A, mol. B, mol.  mer, Silicone num,                                    Comp'n Ratio wt. wt. A/B wt. % wt. % ppm                                    ______________________________________                                        S     1.3/1.0 66800   16200  90/10                                                                              25   75     10                                T 1.3/1.0 66800 16200 80/20 25 75 10                                        ______________________________________                                    

The preparations reported in Table 3 vary the mixture of vinyl siloxanesbeing used to prepare the crosslinked material from that reported inTable 2.

Example 2

Dilution of Crosslinked Gels with Volatile, Low Molecular WeightSilicone Oils

The crosslinked gels prepared in example 1 were further diluted withvolatile, low molecular weight silicone oils to produce a slurry. Thevolatile, low molecular weight silicone oils used for dilution wereeither the same as that used to prepare the crosslinked gel ordifferent. The slurry was subjected to shearing forces in a homogenizerto produce a clear product of a desired viscosity for a specificcosmetic application. The viscosity of the gel volatile slurry that hadbeen subjected to shearing forces ranged from about 100 centistokes toover about 100,000 centistokes at 25° C. Thus for example, 400 g ofpreparation E was blended with 1,600 g of D₄,octamethylcyclotetrasiloxane. Preparation E contains 25 wt. %crosslinked polymer, i.e. 100 g, and therefore the slurry of E in D₄ is5 weight percent polymer. The mixture of 5 percent by weight ("wt. %")crosslinked polymer in D₄ was passed through a Gaulin homogenizer at7,000 psi pressure. The resulting material was clear and had a viscosityof 120,000 centistokes at 25° C. The preparation of other materialaccording to this general procedure is reported in Table 4.

                  TABLE 4                                                         ______________________________________                                        Viscosity of Sheared Crosslinked Silicone Polymers Diluted to 5 Wt. %                                    Wt. % Volatile,                                                                             Low Molecular Viscosity, cps at                                            Comp                                                                         'n Table 1 Gel Wt. % Gel Weight                                               Silicone 25° C.                   ______________________________________                                        AA    A         5        95        28,400                                       BB B 5 95 35,300                                                              CC C 5 95 61,800                                                              DD D 5 95 74,100                                                              EE E 5 95 115,000                                                             FF F 5 95 110,000                                                             GG G 5 95 112,000                                                             HH H 5 95 47,300                                                              II I 5 95 31,400                                                              JJ J 5 95 80,000                                                              KK K 5 95 72,700                                                              LL L 5 95 49,000                                                              MM M 5 95 27,200                                                              NN N 5 95  8,600                                                              OO O 5 95  2,500                                                              PP P 5 95 49,000                                                              QQ Q 5 95 22,000                                                              RR R 5 95  1,800                                                              SS S 5 95 81,700                                                              TT T 5 95 93,100                                                              UU U 6 94 20,000                                                              VV V 3.5 96.5 122,000                                                       ______________________________________                                    

These data indicate that:

1) as hydride to alkenyl (vinyl) ratio is changed through 0.7 to 1.6(hydride) to 1.0 (alkenyl) the product gel viscosity increases;

2) as the molecular weight of the alkenyl component increases, extendingthe distance between crosslink sites,

i) the ability of the initially produced polymer gel to swell upon theaddition of volatile silicones increases and

ii) the viscosity increases; and

3) increasing the average functionality of the alkenyl precursor from1.3 to 2.0, increases the crosslink density and the viscosity of theresulting product.

Example 3

Comparison of Low Crosslink Density Gels with High Crosslink DensityGels

The processed gels of the present invention are gels that have a highcrosslink density, due to the use of the M^(H) Q resin and vinylsiloxanes that a fairly low equivalent weight with respect to the vinylgroup. For purposes of comparison, gels possessing a low densitycrosslinking network were prepared. Thus, the procedures outline toprepare the gels of example one were utilized with a linear hydridesiloxane containing only two equivalents of hydride per molecule and avinyl siloxane containing only two equivalents of vinyl per molecule (onaverage). Thus 2.02 g of a hydrogen terminated siloxane having amolecular weight of about 1,818 and 75 g of a vinyl terminated siloxanehaving a molecular weight of 67,500 were mixed with 425 g ofoctamethylcyclotetrasiloxane. The mixture was stirred and 10 ppmplatinum catalyst was added as previously described. The mixture washeated to 80° C. for five hours. The product was cooled and isolated.The viscosity was 88.5 centistokes at 25° C. The results demonstratethat siloxane polymers made from low functionality ingredients producesiloxane polymers with little crosslinking and thus low efficiency incontrolling the viscosity of the volatile siloxanes.

Elastomer Solids Content

The percent solid elastomer in the product was determined by placing aweighed sample in an oven at 150° C. for 45 minutes and observing theweight loss.

Viscosity

The elastomer/volatile siloxane solutions after processing under flowinduced shear and elongation where evaluated for viscosity 24 hoursafter the processing sample was taken on a Brookfield RVT Viscometerwith a T-C spindle at 4 RPM.

Aesthetic Evaluation

Elastomer/volatile siloxane samples were evaluated for the presence of"gel balls" by applying a small sample to the skin and rubbing until thesolvent spread and evaporated. During this process the presence of verysmall, undesirable balls of silicone were observed in incompletelyprocessed material.

Particle Size

The particle size analysis was done using a Malvern Mastersizer™ fittedwith a 300 mm lens. Applicants note that the particle sizes determinedwill vary as a function of the different type of apparatus used todetermine the particle size. Thus, while a particle size appearsintrinsically to be absolutely determinable, it is in fact governed bythe machine used to measure it. Accordingly, the particle sizes hereinrecited are those determined by a Malvern Mastersizer and should othermachines by used by other practitioners, those machines must bereferenced or calibrated against the sizes as determined by a MalvernMastersizer. The desired material (10 grams) generally containing 5 to10% elastomer swollen with 90-95% cyclic siloxanes was dissolved in a50/50 mixture (40 grams) of isopropanol (IPA) anddecamethylcyclopentasiloxane (D5). This solution was then added toapproximately 500 grams of a 50/50 IPA/D5 that had already been placedin the reservoir of the Malvern Mastersizer. The resulting solution wascirculated through the instrument for five minutes and then triplicatemeasurements were taken. The limits on the Malvern Mastersizer extendfrom 1 to 600 microns with the 300 mm lens. A 45 mm lens was alsoemployed to look for smaller particles with no significant number beingfound. Particles greater than 600 microns such as those that might causegel balls were not visible by this method.

Earlier experiments have shown that the particles prepared in thisinvention are not fully swollen in material as dilute as five percentelastomer content and 95% cyclic siloxanes. However, if the elastomer isfurther diluted below elastomer contents of about three percent, theparticle swells to its full extent. Thus the particle sizes measured inthis experiment demonstrate fully extended particles, while those usedin most applications are of proportionally smaller actual volumedepending on the available solvent. Since for a given particlecomposition it is possible to measure how much additional solvent may beabsorbed, it is possible to back calculate the particle size for anygiven concentration once the full extended particle size is known.Further, it is within the scope of this invention to prepare smallerparticles at a higher elastomer concentration and then swell them at alater time with additional solvent to achieve a larger particle size.

Example 4

Preparation of Elastomer Samples

The elastomer samples were prepared by mixing the low molecular weight,volatile siloxane, vinylsiloxane and silylhydride together and mixing.This was followed by platinum catalyst addition and slow heating to 80°C. to allow cure of the elastomer. This was done with stirring topromote breaking of the resulting elastomer into pieces to accommodatethe ensuing processing steps.

Thus in a typical example 7.28 gm. of [(HMe₂ SiO)₂ SiO]₄ with 0.92%hydride content, 1500 gm. of vinyl terminate polysiloxane containing0.089% vinyl and 4500 gm. of decamethylcyclopentasiloxane were added toa 10 I Drais mixer and allowed to mix at 20° C. Platinum catalyst wasthen added and the temperature slowly brought to 80° C. and held for twohours. The product was then removed from the Drais and used in thefollowing examples.

Example 5

Dilution

The 25% elastomer/volatile siloxane produced above was further dilutedwith the same or a different low molecular weight siloxane before beingsubjected to high, flow induced shear and elongation. Generally the 25%elastomer/volatile siloxane was diluted to about 5 to 7% solid elastomercontent in order to facilitate processing and introduce additionalstress to the crosslinked polysiloxane particle.

In a typical example 450 gm. of 25% elastomer/volatile siloxane wasadded to 1550 gm. of decamethylcyclopentasiloxane and allowed to swellbefore processing. After processing the solution was checked for solidelastomer content by the method described above and found to be 5.62%.

Example 6

Sonolator Processed Material

The diluted solution of elastomer/volatile siloxane was fed to theSonolator unit by a pump such that a constant pressure was maintained onthe orifice. Orifice size was varied through the experiments.Through-put was then measured to determine flow. Processing was doneeither in discreet passes or by recycling to the feed chamber with thenumber of passes being determined by the through-put and processingtime. Samples were taken directly from the end of the sample loop atdesired intervals.

Gaullen Homogenizer

The Gaullen Homogenizer was run in a manner similar to the Sonolatorwith respect to feeds, discreet passes and number of passes with timefor extended samples. The pressure measurement was taken from thepressure measured in the feed chamber controlled by the pressure settingon the orifice pin.

Microfluidizer

The microfluidizer was generally fed material previously diluted andreduced in particle size from well over 1 mm to an average of about 1000microns with a rotor/stator mixer. Material was then pumped through theMicrofluidizer in discreet passes. The Microfluidizer was run using twochambers. In all cases the first was a H30Z chamber and the secondeither a J30Y or a smaller J20Y chamber.

Pressure Related Experiments

A.) The 25% elastomer/volatile siloxane product made above was dilutedto approximately 5.5% solid elastomer content withpentamethylcyclopentasiloxane. The material was cycled through aSonolator at 300 psi and sampled as follows:

    ______________________________________                                        Passes  11.25     33.75     56      112                                       ______________________________________                                        Viscosity                                                                             23150     23450     22450   20100                                       Aesthetics Gel Balls Gel Balls Gel Balls Gel Balls                          ______________________________________                                    

The experiment shows that at low pressure over a very extended number ofcycles the material did not break into sufficiently small particles toform an aesthetically acceptable material of high viscosity.

B.) Similarly, 25% elastomer/volatile siloxane was diluted to 5.62%using decamethylcyclopentasiloxane. The material was processed throughthe Sonolator at 1000 psi and samples taken as follows:

    ______________________________________                                        Passes       18          30                                                   ______________________________________                                        Viscosity    40000       33000                                                  Aesthetics Slight Gel Balls No Gel Balls                                      Particle Size                                                               Peak Center and Volume Area Percent                                                  23.5 micron                                                                             0.50%       2.54%                                              36.5 8.04 19.23                                                               53.0 24.23 31.93                                                              65.1  46.30                                                                   71.7 66.52                                                                  ______________________________________                                    

C.) A 25% elastomer/volatile siloxane made in the manner stated abovewas diluted to 5.5% with decamethylcyclopentasiloxane. The material wasprocessed through a Sonolator at 4500 psi and samples taken as follows:

    ______________________________________                                        Passes       3           4                                                    ______________________________________                                        Viscosity                                                                       Aesthetics No Gel Balls No Gel Balls                                          Particle Size                                                               Peak Center and Volume Percent                                                       13.4 microns                                                                            0.08%       0.28%                                              23.3 3.70 9.11                                                                36.2 9.37 9.14                                                                52.0 12.46 18.31                                                              71.5 74.40                                                                    75.0  63.16                                                                 ______________________________________                                    

Experiments 6 A, B and C show that increasing the flow induced shear andelongation by increasing pressure provides a significantly faster andmore economic (fewer passes to achieve acceptable aesthetics) method forprocessing the crosslinked polysiloxane. At the same time the productviscosity is dramatically higher in high flow induced shear andelongation samples which is a distinct advantage in requiring loweramounts of crosslinked polysiloxane in formulated products wheremaintaining a high viscosity cream is important. The particle sizecomparison of examples 6 B and C shows that the material made with 3passes at high flow induced shear and elongation has a broaderdistribution of particle sizes (more large particles and more smallparticles) than a comparable sample made at lower flow induced shear andelongation. The result of this is that the high flow induced shear andelongation sample has an advantage in containing both higher viscosityfrom large particle sizes and smoother feel during application to theskin from the small particle sizes.

Example 7

A.) A 25% elastomer/volatile siloxane sample prepared as described abovewas diluted to 5% with an 85/15 blend of octamethylcyclotetrasiloxaneand decamethylcyclopentasiloxane. The material was processed in theGaullin Homogenizer as described above at 4000 psi and sampled asfollows:

    ______________________________________                                        Passes        11       45                                                     ______________________________________                                        Viscosity     2640     20300                                                    Aesthetics Gel Balls Few Gel Balls                                            Particle Size                                                               Peak Center and Volume Percent                                                        23.3           4.32                                                     36.2 11.88                                                                    54.3 28.56                                                                    88.3 55.23                                                                  ______________________________________                                    

B.) A 25% elastomer/volatile siloxane sample prepared as described abovewas diluted to 5% with an 85/15 blend of octamethylcyclotetrasiloxaneand decamethylcyclopentasiloxane. The material was processed in theGaullin Homogenizer as described above at 7000 psi and sampled asfollows:

    ______________________________________                                                Passes   5                                                            ______________________________________                                                Viscosity                                                                              78100                                                          Aesthetics No Gel Balls                                                       Particle Size                                                                       Peak Center and Volume Percent                                                  23.3       5.73                                                       36.2 7.48                                                                     52.0 20.26                                                                    88.4 66.52                                                                  ______________________________________                                    

Comparison of examples 7 A and B shows that as the flow induced shearand elongation is increased by increasing the pressure, the number ofpasses required to make acceptable product free of gel balls issignificantly reduced. In addition, with higher flow induced shear andelongation higher viscosity is obtained. Comparison of the particle sizeafter 5 passes at high flow induced shear and elongation is broader thanafter 45 passes at low flow induced shear and elongation. The result isadvantageous in providing higher viscosity from large particles andsuperior feel and flow characteristics from low particle sizes.

Example 8

A.) A 25% elastomer/volatile siloxane sample prepared as described abovewas diluted to 5% with an 85/15 blend of octamethylcyclotetrasiloxaneand decamethylcyclopentasiloxane. The material was processed in theMicrofluidizer at 6,000 psi with a sample taken as follows:

    ______________________________________                                                  Passes 1                                                            ______________________________________                                                  Viscosity                                                                            <10,000                                                        Aesthetics Gel Balls                                                        ______________________________________                                    

B.) A 25% elastomer/volatile siloxane sample prepared as described abovewas diluted to 5% with an 85/15 blend of octamethylcyclotetrasiloxaneand decamethylcyclopentasiloxane. The material was processed in theMicrofluidizer at 18,000 psi with a sample taken as follows:

    ______________________________________                                                 Passes  1                                                            ______________________________________                                                 Viscosity                                                                             >60,000                                                        Aesthetics No Gel Balls                                                     ______________________________________                                    

C.) A 25% elastomer/volatile siloxane sample prepared as described abovewas diluted to 5% with an 85/15 blend of octamethylcyclotetrasiloxaneand decamethylcyclopentasiloxane. The material was processed in theMicrofluidizer at 16,000 psi with the larger J30Y chamber and a sampletaken as follows:

    ______________________________________                                                Passes   1                                                            ______________________________________                                                Viscosity                                                                              84400                                                          Aesthetics No Gel Balls                                                       Particle Size                                                                       Peak Center and Volume Percent                                                  24.3       1.49                                                       36.1 3.91                                                                     51.3 6.98                                                                     71.2 34.58                                                                    117.7 53.03                                                                 ______________________________________                                    

Example 8 A, B and C shows that as flow induced shear and elongation isincreased by increasing the pressure in a Microfluidizer, the product ismore efficiently processed to aesthetically acceptable material havingthe desired high viscosity. The high flow induced shear and elongationalso provides a broad particle size distribution.

Orifice Size Related Experiments

Example 9

A.) A 25% elastomer/volatile siloxane sample prepared as described abovewas diluted to 5% with an 85/15 blend of octamethylcyclotetrasiloxaneand decamethylcyclopentasiloxane. The material was processed in theMicrofluidizer at 16,000 psi with a smaller J20Y chamber and a sampletaken as follows:

    ______________________________________                                                 Pass    1                                                            ______________________________________                                                 Viscosity                                                                             172750                                                         Aesthetics No Gel Balls                                                       Particle Size                                                                        Peak Center and Volume Percent                                                  23.5      0.12                                                       35.8 0.62                                                                     51.9 2.83                                                                     72.7 5.10                                                                     132.7 91.33                                                                 ______________________________________                                    

The comparison of example 9 and example 8 C shows that decreasing theorifice size while maintaining pressure diminishes the breadth ofparticle size distribution.

Example 10

A.) A 25% elastomer/volatile siloxane made in the manner stated abovewas diluted to 5.5% with decamethylcyclopentasiloxane. The material wasprocessed through a Sonolator at 4500 psi with a 0.0021 orifice size andsamples taken as follows:

    ______________________________________                                                  Pass    1                                                           ______________________________________                                                  Viscosity                                                                             NA                                                            Aesthetics Gel Balls                                                          Particle Size                                                                         Peak Center and Volume Percent                                                  23.4      0.69                                                      35.8 2.16                                                                     56.7 15.72                                                                    111.5 81.43                                                                 ______________________________________                                    

B.) A 25% elastomer/volatile siloxane made in the manner stated abovewas diluted to 5.5% with decamethylcyclopentasiloxane. The material wasprocessed through a Sonolator at 4500 psi with a 0.0008 orifice size andsamples taken as follows:

    ______________________________________                                                  Pass    1                                                           ______________________________________                                                  Viscosity                                                                             NA                                                            Aesthetics Gel Balls                                                          Particle Size                                                                         Peak Center and Volume Percent                                                  23.4      0.39                                                      35.8 1.63                                                                     60.7 22.21                                                                    111.5 75.77                                                                 ______________________________________                                    

Example 11

A.) A 25% elastomer/volatile siloxane made in the manner stated abovewas diluted to 5.5% with decamethylcyclopentasiloxane. The material wasprocessed through a Sonolator at 4500 psi with a 0.0021 orifice size andsamples taken as follows:

    ______________________________________                                                   Passes  2                                                          ______________________________________                                                   Particle Size                                                                 Peak Center and Percent Volume                                                  23.5      1.32                                                     36.4 4.35                                                                     51.8 7.90                                                                     71.5 20.06                                                                    118.9 66.36                                                                 ______________________________________                                    

B.) A 25% elastomer/volatile siloxane made in the manner stated abovewas diluted to 5.5% with decamethylcyclopentasiloxane. The material wasprocessed through a Sonolator at 4500 psi with a 0.0008 orifice size andsamples taken as follows:

    ______________________________________                                                   Passes  2                                                          ______________________________________                                                   Particle Size                                                        Peak Center and Volume Percent                                                           23.4      1.39                                                     36.4 4.62                                                                     52.0 7.84                                                                     71.4 21.09                                                                    120.0 65.05                                                                 ______________________________________                                    

Examples 10 A and B demonstrate the broader particle size distributionachieved with a wider orifice size. In these examples the crosslinkedelastomer was not subjected to sufficient shear to achieve the desiredaesthetic standard of no gel balls, and further passes were done. Asfurther passes were made, examples VIII A and B, the particle sizedistribution for each orifice size became similar as the result ofrandomization of the position of the particles as they went through theorifice. In general the effects on particle size distribution of orificesize are less pronounced in the Sonolator than in the Microfluidizerreflecting the shorter orifice path length. Because of the shorter pathlength in the Sonolator, more of the flow induced shear and particleelongation is created as the material is compacted before entering theorifice. Since this is similar for both orifice sizes, the change withorifice size is less dramatic.

Viscosity Related Experiments

Example 12

A 25% elastomer/volatile siloxane made in the manner stated above wasdiluted to 5.5% with decamethylcyclopentasiloxane. 10 weight % of 350cps viscosity polydimethylsiloxane was added and mixed in. Thepolydimethylsiloxane oil was observed not to completely penetrate thecrosslinked polysiloxane elastomer, but rather to coat the surfacecausing a dramatic reduction in viscosity. This viscosity lowering wasobserved through the entire processing step.

The material was processed through a Sonolator with a 0.0008 orifice at1000 psi and samples taken as follows:

    ______________________________________                                        Passes  11        22       34       45   56                                   ______________________________________                                        Viscosity                                                                             400       400      400      400  400                                    Aesthetics Gel Balls Gel Balls No Gel Balls                                   Particle Size                                                               Peak Center and Volume Percent                                                  12.8      0         0      0        0    0                                    23 0.05 0.18 0.40 0.33 0.22                                                   36 0.58 1.83 3.52 4.03 4.50                                                   56  22.79 18.11 10.03 7.27                                                    64 14.58                                                                      75    85.60 88.01                                                             90   77.98                                                                    99  75.20                                                                     140 84.79                                                                   ______________________________________                                    

Comparison of example 12 with example 6 B run at the same pressure,demonstrates that viscosity is critical in producing the particle sizerange. Thus when the viscosity is reduced to about 400 ctks., particlessizes remain too large through more cycles and only very slowly produceparticles of small size. At low viscosity there is lower flow inducedshear and elongation to break up the particles.

Particle Size Distribution Characterization Experiments

In the preparation of the material of the present invention by theprocess of the present invention, depending on the number of passes at agiven pressure, material possessing the three particle size rangesdefined as necessary for the compositions of the present invention canbe prepared in proportions of those particle size ranges that differ andtherefore provide subjective differences in feel.

    ______________________________________                                        Large Average Particle Size                                                     Particle Size Distribution: Material Ranging from about 100 to                600 microns                                                                   Average                                                                       Particle                                                                      Size of                                                                       Population                                                                    microns 10-15 21-26 33-38 50-60 65-80 100 to 300                            ______________________________________                                        Volume  0       0.1-2   0.1-5 1.0-10                                                                              10-50 40-95                                 % Range                                                                       Peak 0 0.1-10   1-10 10-30 25-100 75-200                                      Width at                                                                      Half-                                                                         Height                                                                      ______________________________________                                    

The material having a large average particle size from 100 to 600microns has a thick consistency much like commercial gelatin foodproducts. When applied to the skin, the material is hard to rub into theskin, sticks to itself rather than spreading onto the skin and does notreadily wet the skin and form a thin film.

    ______________________________________                                        Moderate Average Particle Size                                                  Particle Size Distribution: Material Ranging from about 50 to                 150 microns                                                                   Average                                                                       Particle                                                                      Size of                                                                       Population                                                                    microns 10-15 21-26 33-38 50-60 65-80 100 to 300                            ______________________________________                                        Volume  0.1-5   1-5     5-20  10-35 30-80 0-20                                  % Range                                                                       Peak 0.1-3 1-15 5-20 15-40 40-125 75-200                                      Width at                                                                      Half-                                                                         Height                                                                      ______________________________________                                    

The material having a moderate average particle size ranging form 50 to150 microns has a smooth creamy pudding-like consistency. When appliedto the skin, the material exhibits some resistance when rubbed on theskin producing a cushion or sponge like feel that that conveys asubjective perception of a rich fullness.

    ______________________________________                                        Small Average Particle Size                                                     Particle Size Distribution: Material Ranging from about 10 to                 100 microns                                                                   Average                                                                       Particle                                                                      Size of                                                                       Population                                                                    microns 10-15 21-26 33-38 50-60 65-80 100 to 300                            ______________________________________                                        Volume  5-15    15-60   20-50 1-30  0     0                                     % Range                                                                       Peak 2-15  3-20  5-25 5-30 0 0                                                Width at                                                                      Half-                                                                         Height                                                                      ______________________________________                                    

The material having a small average particle size has a thin fluid likeconsistency. When applied to the skin this material spreads readilyacross the skin with little or no resistance and produces an initialheavy or greasy feel. However, once applied to the skin, this materialprovides a smooth silky feel on the skin.

It should be noted that all three of the foregoing examples of acontrolled particle size composition possess the specific particle sizescharacteristically produced by the process.

Preparation of Non-Aqueous Silicone Emulsions

Example 13

A transparent gel anhydrous emulsion useful as an antiperspirant ordeodorant was prepared by blending together two mixtures A and B thatrespectively had the following composition:

    ______________________________________                                        Material                Weight Percent                                        ______________________________________                                        Part A:                                                                         Solution of 40.0 wt. % dimethicone copolyol in 2.5                            cyclomethicone                                                                Swollen elastomer (elastomer gel swollen with 7.0                             cyclomethicone, as in example 12)                                             Phenyl trimethicone 14.5                                                      Part B:                                                                       Polysorbate 80 ®  0.25                                                    Propylene glycol 47.42                                                        30% ZAC in propylene glycol 23.33                                             Ethanol 5.00                                                                ______________________________________                                    

The preparation was accomplished as follows:

1) the ingredients comprising part A were mixed together;

2) reserving 3 percent of the propylene glycol for later use, thePolysorbate 80® and ethanol were dissolved in the propylene glycol;

3) the ZAG solution in propylene glycol (30 wt. % aluminum zirconiumpentachlorohydrex GLY) was added to the Polysorbate 80® and ethanolpropylene glycol solution;

4) the refractive indices of both parts A and B were measured andadjusted using liquids of different refractive index such that therefractive index of part B was matched to the refractive index of part Ato within 0.00010 RI units;

5) part B was slowly added to part A once the desired match inrefractive index was achieved using moderate shear mixing which wasgradually increased as the mixture thickened and agitation was continuedin this fashion for fifteen minutes; and

6) homogenize for approximately two minutes with a high speed high shearmixer such as an Eppenbach™ mixer.

The purpose of matching the refractive index of the two phasescomprising the emulsion is to prepare an emulsion that is transparent tothe naked eye, irrespective of the particle sizes of the dispersedphase. Thus by matching the refractive indices of the two immisciblephases, embodiments of the present invention that are transparent may beprepared. This may be accomplished by the addition of suitable liquidcomponents to either phase that have, as appropriate, either higher orlower indices of refraction.

Examples 14 and 15

The procedure of example 13 was followed using:

    ______________________________________                                        Material                Weight Percent                                        ______________________________________                                        Part A:                                                                         Solution of 40.0 wt. % dimethicone copolyol in 2.5                            cyclomethicone                                                                Swollen elastomer (elastomer gel swollen with 7.0                             cyclomethicone, as in example 12)                                             Phenylpropyl siloxane 14.5                                                    Part B:                                                                       Polysorbate 80 ®  0.25                                                    Propylene glycol 55.75                                                        35% ZAG4 (35 wt. % aluminum zirconium 20.00                                   tetrachlorohydrex GLY) in propylene glycol                                  ______________________________________                                    

After the addition of part B to part A the sample was split into twomore or less equal fractions, example 14 was not homogenized whileexample 15 was homogenized for approximately 2 minutes using theEppenbach™ homogenizer. The materials as prepared were measured forviscosity using a Brookfield viscometer at 25° C., tested for stabilityat room temperature, at 40° C., and under freeze-thaw conditions. Table5 shows the viscosities and stabilities.

                  TABLE 5                                                         ______________________________________                                        Comparative Viscosities and Stabilities of Homogenized and Un-                  Homogenized Non-Aqueous Emulsions                                                           Example 14  Example 15                                        ______________________________________                                        Homogenized     No          Yes                                                 Initial Viscosity, cps at 26,000 64,500                                       25° C.                                                                 Viscosity after 5 freeze 27,000 64,500                                        thaw cycles, cps at 25° C.                                             Stability at Room unchanged unchanged                                         Temperature, 1 month                                                          Stability at Room unchanged unchanged                                         Temperature, 2 months                                                         Stability at 40° C., 1 unchanged unchanged                             month                                                                         Stability at 40° C., 2 unchanged unchanged                             months                                                                        Stability after 10 freeze flowable but not unchanged                          thaw cycles separated                                                       ______________________________________                                    

These examples demonstrate that emulsions of the present invention arestable irrespective of whether high shear homogenization is employed inthe preparation.

Example 16

The procedure of example 13 was followed using:

    ______________________________________                                        Material                Weight Percent                                        ______________________________________                                        Part A:                                                                         Solution of 40.0 wt. % dimethicone copolyol in 2.5                            cyclomethicone                                                                Swollen elastomer (elastomer gel swollen with 0.0                             cyclomethicone)                                                               Cyclomethicone 7.0                                                            Phenylpropyl siloxane 14.5                                                    Part B:                                                                       Polysorbate 80 ®  0.25                                                    Propylene glycol 55.75                                                        35% ZAG4 in propylene glycol 20.00                                          ______________________________________                                    

                  TABLE 6                                                         ______________________________________                                        Comparative Viscosities and Stabilities of Homogenized                          Non-Aqueous Emulsions With and Without Swollen Elastomer Gel                                Example 16  Example 15                                        ______________________________________                                        Swollen Elastomer Gel                                                                         No          Yes                                                 Initial Viscosity, cps at 31,000 64,500                                       25° C.                                                                 Viscosity after 5 freeze 22,000 64,500                                        thaw cycles, cps at 25° C.                                             Stability at Room unchanged unchanged                                         Temperature, 1 month                                                          Stability at Room unchanged unchanged                                         Temperature, 2 months                                                         Stability at 40° C., 1 unchanged unchanged                             month                                                                         Stability at 40° C., 2 unchanged unchanged                             months                                                                        Stability after 10 freeze flowable but not unchanged                          thaw cycles separated                                                       ______________________________________                                    

Material Descriptions

1. Cyclomethicone is a mixture of volatile cyclic dimethyl siloxaneshaving the general formula ((CH₃)₂ SiO)_(x) where x ranges from 3 to 6.

2. Dimethicone copolyol is a copolymeric siloxane that ispolyoxyalkylene modified having the formula MD500D'6.5M where M=((CH₃)₃SiO_(1/2), D=(CH₃)₂ SiO_(2/2) and D'=(CH₃)SiO((OC₂ H₄)₂₀.5 (OC₃ H₆)₁₅.5OH.

3. Phenyltrimethicone is (C₆ H₅)Si(OSi(CH₃)₃)₃.

4. Phenylpropyl siloxane is M'D₃ M' where M' is ((C₆H₅)CH(CH₃)CH₂)(CH₃)₂ SiO_(1/2) and D is as defined above for dimethiconecopolyol or MD"M where M is as defined above for dimethicone copolyoland D" is ((C₆ H₅)CH(CH₃)CH₂)(CH₃)SiO_(2/2).

5. Swollen elastomer gel (the silicone composition of the instantinvention) is the addition product of M^(Vi) _(a) D_(x) D^(vi) _(y)M_(2-a) and (M^(H) _(w) Q_(z))_(j) in the presence of a second siliconehaving a viscosity below about 1,000 centistokes at 25° C. where theaddition product is a gel and particle size distribution of the gel iscontrolled and comprises:

a) a local maximum ranging from about 21 to about 26 microns;

b) a local maximum ranging from about 33 to about 38 microns,

c) and a local maximum ranging from about 50 to 60 microns.

These examples demonstrate that emulsions that do not contain theswollen elastomer dispersion do not possess freeze thaw stability.

Examples 17 and 18

A transparent solid anhydrous emulsion useful as an antiperspirant wasprepared by blending together two mixtures A and B that respectively hadthe following composition:

    ______________________________________                                        Material                  Weight Percent                                      ______________________________________                                        Part A:                                                                         Solution of 40.0 wt. % dimethicone copolyol in                                                            2.5                                               cyclomethicone                                                                Swollen elastomer, marketed as "Gransil ™" 7.0                             (elastomer gel swollen with                                                   cyclomethicone, as described in U.S. Pat. No. 5,571,853)                      Phenylpropyl siloxane 14.5                                                  Part B:                                                                         Polysorbate 80 ®        0.25                                              Propylene glycol 55.75                                                        35% ZAG4 in propylene glycol 20.00                                          ______________________________________                                    

The preparation was accomplished as follows:

1) the ingredients comprising part A were mixed together;

2) reserving 3 percent of the propylene glycol for later use, thePolysorbate 80® and ethanol were dissolved in the propylene glycol;

3) the ZAG solution in propylene glycol was added to the Polysorbate 80®and ethanol propylene glycol solution;

4) the refractive indices of both parts A and B were measured andadjusted using liquids of different refractive index such that therefractive index of part B was matched to the refractive index of part Ato within 0.00010 RI units;

5) part B was slowly added to part A once the desired match inrefractive index was achieved using moderate shear mixing which wasgradually increased as the mixture thickened and agitation was continuedin this fashion for fifteen minutes; and

6) homogenize for approximately two minutes with a high speed high shearmixer such as an Eppenbach™ mixer.

After the addition of part B to part A the sample was split into twomore or less equal fractions, example 17 was not homogenized whileexample 18 was homogenized for approximately 2 minutes using theEppenbach™ homogenizer. The materials as prepared were measured forviscosity using a Brookfield viscometer at 25° C., tested for stabilityat room temperature, at 40° C., and under freeze-thaw conditions. Table7 shows the viscosities and stabilities.

                  TABLE 7                                                         ______________________________________                                        Comparative Viscosities and Stabilities of Homogenized and Un-                  Homogenized Non-Aqueous Emulsions                                                        Example 17    Example 18                                         ______________________________________                                        Homogenized  No            Yes                                                  Initial Viscosity, cps at 17,000 28,000                                       25° C.                                                                 Viscosity after 5 freeze 17,000 28,000                                        thaw cycles, cps at                                                           25° C.                                                                 Stability at Room N/A N/A                                                     Temperature, 1 month                                                          Stability at Room N/A N/A                                                     Temperature, 2 months                                                         Stability at 40° C., 1 N/A N/A                                         month                                                                         Stability at 40° C., 2 N/A N/A                                         months                                                                        Stability after 10 freeze no change in viscosity no change in viscosity       thaw cycles                                                                 ______________________________________                                    

These examples demonstrate that a swollen elastomer enables preparationof a non-aqueous emulsion irrespective of the components used to preparethe elastomer.

Example 19

The procedure of example 13 was followed with the exception of step 6,homogenization, using:

    ______________________________________                                        Material                Weight Percent                                        ______________________________________                                        Part A:                                                                           Solution of 40.0 wt. % dimethicone copolyol in                                                        2.5                                                 cyclomethicone                                                                Cyclomethicone 7.0                                                            Phenylpropyl siloxane 14.5                                                  Part B:                                                                           Polysorbate 80 ®    0.25                                                Propylene glycol 55.75                                                        35% ZAG4 in propylene glycol 20.00                                          ______________________________________                                    

The material prepared in example 19 separated into three immiscibleliquid layers after one freeze thaw cycle. These results demonstratethat dispersions of silicone elastomers in a carrier solvent stabilizenon-aqueous emulsions. Further, these results indicate that thestabilizing effect of the elastomer dispersion is not dependent upon theprecursor alkenyl siloxane and organohydrogen siloxane compounds used toprepare the elastomer.

As non-limiting examples of a base compositions comprising the emulsionsof the present invention whereby cosmetic, personal care and drugdelivery system compositions could be prepared, the following examplesare presented by comparison to similar preparations that do not containthe non-aqueous emulsion stabilizing elastomer gel.

Examples 20 and

    ______________________________________                                        Component        Example 20                                                                              Example 21                                         ______________________________________                                        Part A                                                                            Solution of 10.0 wt. %                                                                         20.0      20                                               dimethicone copolyol in                                                       cyclomethicone, parts by                                                      weight                                                                        Cyclomethicone, parts by 12.5 0                                               weight                                                                        Elastomer gel swollen 0 12.5                                                  with cyclomethicone,                                                          parts by weight                                                             Part B                                                                            Propylene glycol, parts                                                                        67.5      67.5                                             by weight                                                                   ______________________________________                                    

The materials of examples 20 and 21 were mixed together as follows:

1) the ingredients of part A were mixed together; and

2) part B was slowly added to part A using moderate shear mixing.

The materials as prepared were measured for viscosity using a Brookfieldviscometer at 25° C. and tested for stability at room temperature, 40°C., and under freeze thaw conditions. Examples 20 and 21 as prepared arecloudy or translucent, indicating they are both emulsions. This isindicative that the propylene glycol and silicone have formed anemulsion consisting of a continuous and a discontinuous phases and bothphases are non-aqueous. Table 8 shows the viscosities and stabilities.

                  TABLE 8                                                         ______________________________________                                        Comparison of Non-Aqueous Emulsion Cosmetic Base with and                       without Elastomer Gel Swollen by Silicone Oil                                 Property        Example 20  Example 21                                      ______________________________________                                        Elastomer Gel swollen                                                                       No          Yes                                                   with silicone oil, present?                                                   Viscosity, initial, cps at 2,800 8,600                                        25° C.                                                                 Stability, room separated into two homogeneous emulsion,                      temperature, 3 days layers unchanged                                          Stability at 40° C., separated into two homogeneous emulsion,                                   7 days layers unchanged                              Stability after 3 freeze separated into two homogeneous emulsion,                                      thaw cycles layers unchanged                         Viscosity after 3 freeze N/A 3,300                                            thaw cycles                                                                 ______________________________________                                    

The incorporation of the silicone oil swollen silicone elastomer enablesthe preparation of stable non-aqueous emulsions of other silicones withnon-aqueous organic hydroxylic solvents and serves to provide a basiccomposition useful as a base for a variety of cosmetic and personal carecompositions as well as providing a component for topical drug deliverysystems. The stability is improved by preservation of the emulsion overthree freeze thaw cycles in contrast to the preparation where theelastomer was absent. The stability is improved by preservation of theemulsion against separation into distinct liquid phases for a period ofat least three days at room temperature, and a period of at least sevendays at 40° C. Thus stability is herein defined as no visible phaseseparation of the immiscible phases after a given period of time at agiven temperature, i.e. a matter of days at a given temperature.

Examples 22 and

    ______________________________________                                        Component        Example 22                                                                              Example 23                                         ______________________________________                                        Part A                                                                            Solution of 10.0 wt. %                                                                         20.0      20                                               dimethicone copolyol in                                                       cyclomethicone, parts by                                                      weight                                                                        Cyclomethicone, parts by 12.5 0                                               weight                                                                        Elastomer gel swollen 0 12.5                                                  with cyclomethicone,                                                          parts by weight                                                             Part B                                                                            Propylene glycol, parts                                                                        67.0      67.0                                             by weight                                                                     Sodium Chloride, parts 0.5 0.5                                                by weight.                                                                  ______________________________________                                    

The materials of examples 22 and 23 were mixed together as follows:

1) the ingredients of part A were mixed together; and

2) part B was slowly added to part A using moderate shear mixing.

The materials as prepared were measured for viscosity using a Brookfieldviscometer at 25° C. and tested for stability at room temperature, 40°C., and under freeze thaw conditions. Examples 22 and 23 as prepared arecloudy or translucent, indicating they are both emulsions. This isindicative that the propylene glycol and silicone have formed anemulsion consisting of a continuous and a discontinuous phases and bothphases are non-aqueous. Table 9 shows the viscosities and stabilities.

                  TABLE 9                                                         ______________________________________                                        Comparison of Non-Aqueous Emulsion Cosmetic Base with and                       without Elastomer Gel Swollen by Silicone Oil                                 Property        Example 22  Example 23                                      ______________________________________                                        Elastomer Gel swollen                                                                       No          Yes                                                   with silicone oil; present?                                                   Viscosity, initial, cps at 4,400 17,200                                       25° C.                                                               Stability, room                                                                             separated into two                                                                        homogeneous emulsion,                                 temperature, 11 days layers unchanged                                         Stability at 40° C., 9 days separated into two homogeneous                                     emulsion,                                              layers unchanged                                                           Viscosity after 5 freeze                                                                    3,700       16,500                                                thaw cycles, cps at 25° C.                                             Percent change in -18.9 -4.24                                                 viscosity after 5 freeze                                                      thaw cycles.                                                                ______________________________________                                    

The incorporation of the silicone oil swollen silicone elastomer enablesthe preparation of stable salt-comprising (e.g. NaCl) non-aqueousemulsions of other silicones with non-aqueous organic hydroxylicsolvents and serves to provide a basic composition useful as a base fora variety of cosmetic and personal care compositions as well asproviding a component for topical drug delivery systems. The stabilityis improved by preservation of the emulsion over five freeze thaw cyclesin contrast to the preparation where the elastomer was absent. Thestability is improved by preservation of the emulsion against separationinto distinct liquid phases for a period of at least eleven days at roomtemperature, and a period of at least nine days at 40° C. Stability isherein defined as no visible phase separation of the immiscible phasesafter a given period of time at a given temperature, i.e. a matter ofdays at a given temperature.

Having described the invention, that which is claimed is:
 1. Anon-aqueous silicone emulsion, comprising:a silicone phase, comprising acrosslinked silicone elastomer and a low molecular weight siliconefluid; and an organic phase, comprising an organic liquid wherein theorganic phase comprises less than 50 parts by weight water per 100 partsby weight of the organic phase.
 2. The emulsion of claim 1, wherein thesilicone phase is a continuous phase, the organic phase is adiscontinuous phase and the discontinuous organic phase is dispersed inthe continuous silicone phase.
 3. The emulsion of claim 1, wherein theemulsion comprises from 0.1 parts by weight to 99.9 parts by weight ofthe silicone phase and from 0.1 parts by weight to 99.9 parts by weightof the organic phase.
 4. The emulsion of claim 1, wherein the siliconephase comprises from 0.005 parts by weight to 30 parts by weight of thecrosslinked silicone elastomer and from 70 parts by weight to 99.995parts by weight of the low molecular weight silicone.
 5. The emulsion ofclaim 1, wherein the crosslinked silicone elastomer is the reactionproduct of a hydrosilylation reaction between an alkenyl siliconeprecursor and a hydrogen silicone precursor.
 6. The emulsion of claim 5,wherein the alkenyl silicone precursor is organosiloxane ororganopolysiloxane having two or more alkenyl groups per molecule onaverage.
 7. The emulsion of claim 6, wherein the alkenyl siliconeprecursor is an a linear alkenyl stopped polyorganosiloxane having theformula:

    M.sup.vi.sub.a D.sub.x D.sup.vi.sub.y M.sub.2-a

where the subscript x is a number greater than 500, the subscript y is anumber ranging from zero to about 20, the subscript a is a numberranging from 0 to 2, subject to the limitation that a+y is within therange of from 1 to about 20, with M^(vi) defined as:

    R.sup.1 R.sup.2 R.sup.3 SiO.sub.1/2

where R¹ is a monovalent unsaturated hydrocarbon radical having from twoto ten carbon atoms, and R² and R³ are each independently one to fortycarbon atom monovalent hydrocarbon radicals, with D defined as:

    R.sup.4 R.sup.5 SiO.sub.2/2

where R⁴ and R⁵ are each independently one to forty carbon atommonovalent hydrocarbon radicals, with D^(vi) defined as:

    D.sup.vi =R.sup.6 R.sup.7 SiO.sub.2/2

where R⁶ is a monovalent unsaturated hydrocarbon radical having from twoto ten carbon atoms, and R⁷ is independently a one to forty carbon atommonovalent hydrocarbon radical with M defined as:

    M=R.sup.8 R.sup.9 R.sup.10 SiO.sub.1/2

with R⁸, R⁹, and R¹⁰ each independently a one to forty carbon atommonovalent hydrocarbon radical.
 8. The emulsion of claim 5 wherein thehydrogen silicone precursor is an organohydrogensiloxane having two ormore silicon hydride groups per molecule on average.
 9. The emulsion ofclaim 8 wherein the hydrogen silicone precursor is a resin having theformula:

    (M.sup.H.sub.w Q.sub.z).sub.j

where Q has the formula SiO_(4/2) and where M^(H) has the formula H_(b)R¹¹ _(3-b) SiO_(1/2) with the subscript b ranging from 1 to 3, where R¹¹is a one to forty carbon atom monovalent hydrocarbon radical; with thesubscripts w and z having a ratio of 0.5 to 4.0 respectively, and thesubscript j ranging from about 2.0 to about
 100. 10. The emulsion ofclaim 1, wherein the low molecular weight silicone comprises has aviscosity below about 1,000 centistokes at 25° C.
 11. The emulsion ofclaim 10 wherein the low molecular weight silicone is selected from thegroup consisting of D₃, D₄, D₅, D₆ and M'D'_(i) M' and mixtures thereofwhere D is defined as:

    R.sup.4 R.sup.5 SiO.sub.2/2

where R⁴ and R⁵ are each independently one to forty carbon atommonovalent hydrocarbon radicals and D' is independently defined as:

    R.sup.4 R.sup.5 SiO.sub.2/2

where R⁴ and R⁵ are each independently one to forty carbon atommonovalent hydrocarbon radicals and M' independently has the formula

    R.sup.12 R.sup.13 R.sup.14 SiO.sub.1/2

where R¹², R¹³ and R¹⁴ are each independently selected from the group ofone to forty carbon atom monovalent hydrocarbon radicals and thesubscript i ranges from 0 to about
 300. 12. The emulsion of claim 11,wherein low molecular weight silicone is selected from the groupconsisting of D₃, D₄, D₅, D₆ and mixtures thereof.
 13. The emulsion ofclaim 1, wherein the organic liquid is selected from the groupconsisting of ethylene glycol, ethanol, propyl alcohol, iso-propylalcohol, propylene glycol, dipropylene glycol, tripropylene glycol,butylene glycol, iso-butylene glycol, methyl propane diol, glycerin,sorbitol, polyethylene glycol, polypropylene glycol mono alkyl ethers,polyoxyalkylene copolymers and mixtures thereof.
 14. The emulsion ofclaim 13 wherein said non-aqueous organic hydroxylic solvent ispropylene glycol.
 15. The emulsion of claim 5, wherein thehydrosilylation reaction is carried out in the presence of a firstportion of the low molecular weight silicone to thereby form a gel. 16.The emulsion of claim 15, wherein the gel is slurried in a secondportion of the low molecular weight silicone and the slurry so formed isthen subjected to further mixing to form a mixture.
 17. A personal carecomposition comprising the emulsion of claim
 1. 18. The personal carecomposition of claim 17, wherein the composition is selected fromdeodorants, antiperspirants, facial creams, shampoos, mousses, stylinggels, sunscreens, lipsticks, foundations, blushes, makeups, andmascaras.
 19. A personal care composition, comprising the non-aqueousemulsion of claim 1 and one or more water-sensitive dermatologicalactive agents or cosmetic active agents.
 20. A deodorant composition,comprising the non-aqueous emulsion of claim 1 and one or moreanti-microbial agents.
 21. An antiperspirant composition, comprising thenon-aqueous emulsion of claim 1 and one or more active antiperspirantagents.
 22. A skin cream composition , comprising the non-aqueousemulsion of claim 1 and an emollient.
 23. A sunscreen compositioncomprising the non-aqueous emulsion of claim 1 and one or more agentsfor absorbing ultraviolet radiation.
 24. A method for making anonaqueous silicone emulsion, comprisingadding a silicone elastomer anda first portion of a low molecular weight silicone together, therebyforming a silicone gel, slurrying the gel with a second portion of thelow molecular weight silicone to form a mixture having a desiredparticle size, thereby forming a silicone phase, and combining thesilicone phase with an organic solvent to form the emulsion.
 25. Themethod of claim 24, wherein the silicone phase is a continuous phase,the organic phase is a discontinuous phase and the discontinuous organicphase is dispersed in the continuous phase.
 26. The emulsion of claim 1,wherein the organic liquid is a polar liquid that exhibits a dipolemoment of from 0.9 to 4.5.
 27. The emulsion of claim 1, wherein theorganic liquid is a hydroxylic liquid.
 28. The emulsion of claim 1,wherein the organic phase comprises less than 30 parts by weight waterper 100 parts by weight of the organic phase.
 29. The emulsion of claim1, wherein the organic phase comprises less than 10 parts by weightwater per 100 parts by weight of the organic phase.
 30. The emulsion ofclaim 1, wherein the organic phase comprises less than 1 parts by weightwater per 100 parts by weight of the organic phase.